My Cruiser Life Magazine
Basics of Sailboat Hull Design – EXPLAINED For Owners
There are a lot of different sailboats in the world. In fact, they’ve been making sailboats for thousands of years. And over that time, mankind and naval architects (okay, mostly the naval architects!) have learned a thing or two.
If you’re wondering what makes one sailboat different from another, consider this article a primer. It certainly doesn’t contain everything you’d need to know to build a sailboat, but it gives the novice boater some ideas of what goes on behind the curtain. It will also provide some tips to help you compare different boats on the water, and hopefully, it will guide you towards the sort of boat you could call home one day.
Table of Contents
Displacement hulls, semi displacement hulls, planing hulls, history of sailboat hull design, greater waterline length, distinctive hull shape and fin keel designs, ratios in hull design, the hull truth and nothing but the truth, sail boat hull design faqs.
Basics of Hull Design
When you think about a sailboat hull and how it is built, you might start thinking about the shape of a keel. This has certainly spurred a lot of different designs over the years, but the hull of a sailboat today is designed almost independently of the keel.
In fact, if you look at a particular make and model of sailboat, you’ll notice that the makers often offer it with a variety of keel options. For example, this new Jeanneau Sun Odyssey comes with either a full fin bulb keel, shallow draft bulb fin, or very shallow draft swing keel. Where older long keel designs had the keel included in the hull mold, today’s bolt-on fin keel designs allow the manufacturers more leeway in customizing a yacht to your specifications.
What you’re left with is a hull, and boat hulls take three basic forms.
- Displacement hull
- Semi-displacement hulls
- Planing hulls
Most times, the hull of a sailboat will be a displacement hull. To float, a boat must displace a volume of water equal in weight to that of the yacht. This is Archimedes Principle , and it’s how displacement hulled boats get their name.
The displacement hull sailboat has dominated the Maritimes for thousands of years. It has only been in the last century that other designs have caught on, thanks to advances in engine technologies. In short, sailboats and sail-powered ships are nearly always displacement cruisers because they lack the power to do anything else.
A displacement hull rides low in the water and continuously displaces its weight in water. That means that all of that water must be pushed out of the vessel’s way, and this creates some operating limitations. As it pushes the water, water is built up ahead of the boat in a bow wave. This wave creates a trough along the side of the boat, and the wave goes up again at the stern. The distance between the two waves is a limiting factor because the wave trough between them creates a suction.
This suction pulls the boat down and creates drag as the vessel moves through the water. So in effect, no matter how much power is applied to a displacement hulled vessel, it cannot go faster than a certain speed. That speed is referred to as the hull speed, and it’s a factor of a boat’s length and width.
For an average 38 foot sailboat, the hull speed is around 8.3 knots. This is why shipping companies competed to have the fastest ship for many years by building larger and larger ships.
While they might sound old-school and boring, displacement hulls are very efficient because they require very little power—and therefore very little fuel—to get them up to hull speed. This is one reason enormous container ships operate so efficiently.
Of course, living in the 21st century, you undoubtedly have seen boats go faster than their hull speed. Going faster is simply a matter of defeating the bow wave in one way or another.
One way is to build the boat so that it can step up onto and ride the bow wave like a surfer. This is basically what a semi-displacement hull does. With enough power, this type of boat can surf its bow wave, break the suction it creates and beat its displacement hull speed.
With even more power, a boat can leave its bow wave in the dust and zoom past it. This requires the boat’s bottom to channel water away and sit on the surface. Once it is out of the water, any speed is achievable with enough power.
But it takes enormous amounts of power to get a boat on plane, so planing hulls are hardly efficient. But they are fast. Speedboats are planing hulls, so if you require speed, go ahead and research the cost of a speedboat .
The most stable and forgiving planing hull designs have a deep v hull. A very shallow draft, flat bottomed boat can plane too, but it provides an unforgiving and rough ride in any sort of chop.
If you compare the shapes of the sailboats of today with the cruising boat designs of the 1960s and 70s, you’ll notice that quite a lot has changed in the last 50-plus years. Of course, the old designs are still popular among sailors, but it’s not easy to find a boat like that being built today.
Today’s boats are sleeker. They have wide transoms and flat bottoms. They’re more likely to support fin keels and spade rudders. Rigs have also changed, with the fractional sloop being the preferred setup for most modern production boats.
Why have boats changed so much? And why did boats look so different back then?
One reason was the racing standards of the day. Boats in the 1960s were built to the IOR (International Offshore Rule). Since many owners raced their boats, the IOR handicaps standardized things to make fair play between different makes and models on the racecourse.
The IOR rule book was dense and complicated. But as manufacturers started building yachts, or as they looked at the competition and tried to do better, they all took a basic form. The IOR rule wasn’t the only one around . There were also the Universal Rule, International Rule, Yacht Racing Association Rul, Bermuda Rule, and a slew of others.
Part of this similarity was the rule, and part of it was simply the collective knowledge and tradition of yacht building. But at that time, there was much less distance between the yachts you could buy from the manufacturers and those setting off on long-distance races.
Today, those wishing to compete in serious racing a building boat’s purpose-built for the task. As a result, one-design racing is now more popular. And similarly, pleasure boats designed for leisurely coastal and offshore hops are likewise built for the task at hand. No longer are the lines blurred between the two, and no longer are one set of sailors “making do” with the requirements set by the other set.
Modern Features of Sailboat Hull Design
So, what exactly sets today’s cruising and liveaboard boats apart from those built-in decades past?
Today’s designs usually feature plumb bows and the maximum beam carried to the aft end. The broad transom allows for a walk-through swim platform and sometimes even storage for the dinghy in a “garage.”
The other significant advantage of this layout is that it maximizes waterline length, which makes a faster boat. Unfortunately, while the boats of yesteryear might have had lovely graceful overhangs, their waterline lengths are generally no match for newer boats.
The wide beam carried aft also provides an enormous amount of living space. The surface area of modern cockpits is nothing short of astounding when it comes to living and entertaining.
If you look at the hull lines or can catch a glimpse of these boats out of the water, you’ll notice their underwater profiles are radically different too. It’s hard to find a full keel design boat today. Instead, fin keels dominate, along with high aspect ratio spade rudders.
The flat bottom boats of today mean a more stable boat that rides flatter. These boats can really move without heeling over like past designs. Additionally, their designs make it possible in some cases for these boats to surf their bow waves, meaning that with enough power, they can easily achieve and sometimes exceed—at least for short bursts—their hull speeds. Many of these features have been found on race boats for decades.
There are downsides to these designs, of course. The flat bottom boats often tend to pound when sailing upwind , but most sailors like the extra speed when heading downwind.
How Do You Make a Stable Hull
Ultimately, the job of a sailboat hull is to keep the boat afloat and create stability. These are the fundamentals of a seaworthy vessel.
There are two types of stability that a design addresses . The first is the initial stability, which is how resistant to heeling the design is. For example, compare a classic, narrow-beamed monohull and a wide catamaran for a moment. The monohull has very little initial stability because it heels over in even light winds. That doesn’t mean it tips over, but it is relatively easy to make heel.
A catamaran, on the other hand, has very high initial stability. It resists the heel and remains level. Designers call this type of stability form stability.
There is also secondary stability, or ultimate stability. This is how resistant the boat is to a total capsize. Monohull sailboats have an immense amount of ballast low in their keels, which means they have very high ultimate stability. A narrow monohull has low form stability but very high ultimate stability. A sailor would likely describe this boat as “tender,” but they would never doubt its ability to right itself after a knock-down or capsize.
On the other hand, the catamaran has extremely high form stability, but once the boat heels, it has little ultimate stability. In other words, beyond a certain point, there is nothing to prevent it from capsizing.
Both catamarans and modern monohulls’ hull shapes use their beams to reduce the amount of ballast and weight . A lighter boat can sail fast, but to make it more stable, naval architects increase the beam to increase the form stability.
If you’d like to know more about how stable a hull is, you’ll want to learn about the Gz Curve , which is the mathematical calculation you can make based on a hull’s form and ultimate stabilities.
How does a lowly sailor make heads or tails out of this? You don’t have to be a naval architect when comparing different designs to understand the basics. Two ratios can help you predict how stable a design will be .
The first is the displacement to length ratio . The formula to calculate it is D / (0.01L)^3 , where D is displacement in tons and L is waterline length in feet. But most sailboat specifications, like those found on sailboatdata.com , list the D/L Ratio.
This ratio helps understand how heavy a boat is for its length. Heavier boats must move more water to make way, so a heavy boat is more likely to be slower. But, for the ocean-going cruiser, a heavy boat means a stable boat that requires much force to jostle or toss about. A light displacement boat might pound in a seaway, and a heavy one is likely to provide a softer ride.
The second ratio of interest is the sail area to displacement ratio. To calculate, take SA / (D)^0.67 , where SA is the sail area in square feet and D is displacement in cubic feet. Again, many online sites provide the ratio calculated for specific makes and models.
This ratio tells you how much power a boat has. A lower ratio means that the boat doesn’t have much power to move its weight, while a bigger number means it has more “get up and go.” Of course, if you really want to sail fast, you’d want the boat to have a low displacement/length and a high sail area/displacement.
Multihull Sailboat Hulls
Multihull sailboats are more popular than ever before. While many people quote catamaran speed as their primary interest, the fact is that multihulls have a lot to offer cruising and traveling boaters. These vessels are not limited to coastal cruising, as was once believed. Most sizable cats and trimarans are ocean certified.
Both catamarans and trimaran hull designs allow for fast sailing. Their wide beam allows them to sail flat while having extreme form stability.
Catamarans have two hulls connected by a large bridge deck. The best part for cruisers is that their big surface area is full of living space. The bridge deck usually features large, open cockpits with connecting salons. Wrap around windows let in tons of light and fresh air.
Trimarans are basically monohulls with an outrigger hull on each side. Their designs are generally less spacious than catamarans, but they sail even faster. In addition, the outer hulls eliminate the need for heavy ballast, significantly reducing the wetted area of the hulls.
Boaters and cruising sailors don’t need to be experts in yacht design, but having a rough understanding of the basics can help you pick the right boat. Boat design is a series of compromises, and knowing the ones that designers and builders take will help you understand what the boat is for and how it should be used.
What is the most efficient boat hull design?
The most efficient hull design is the displacement hull. This type of boat sits low in the water and pushes the water out of its way. It is limited to its designed hull speed, a factor of its length. But cruising at hull speed or less requires very little energy and can be done very efficiently.
By way of example, most sailboats have very small engines. A typical 40-foot sailboat has a 50 horsepower motor that burns around one gallon of diesel every hour. In contrast, a 40-foot planing speedboat may have 1,000 horsepower (or more). Its multiple motors would likely be consuming more than 100 gallons per hour (or more). Using these rough numbers, the sailboat achieves about 8 miles per gallon, while the speedboat gets around 2 mpg.
What are sail boat hulls made of?
Nearly all modern sailboats are made of fiberglass.
Traditionally, boats were made of wood, and many traditional vessels still are today. There are also metal boats made of steel or aluminum, but these designs are less common. Metal boats are more common in expedition yachts or those used in high-latitude sailing.
Matt has been boating around Florida for over 25 years in everything from small powerboats to large cruising catamarans. He currently lives aboard a 38-foot Cabo Rico sailboat with his wife Lucy and adventure dog Chelsea. Together, they cruise between winters in The Bahamas and summers in the Chesapeake Bay.
The Olson 30: Ultra Light, Ultra Fast
The complete book of sailboat buying, volume ii, june, 1987.
by Editors of the Practical Sailor
The first project for Pacific Boats was the Olson 30, which was put into production in 1978. Over 200 of these 3600-pound ULDBs were sold, and the builder claims they have gathered in sufficient numbers to support one-design racing in Seattle, the Great Lakes, Annapolis, Texas, and Long Island Sound, as well as several spots in California. Pacific Boats was a small firm that built only the Olson 30 and the Olson 40, both to quality standards.
CONSTRUCTION
Some people wonder how the ULDB can be built so light and still be seaworthy offshore. The answer lies in the fact that a light boat is subjected to much lighter loads than a heavy boat when pounding through a sea (there is tremendous saving in weight with a stripped-out interior). And perhaps more importantly, ULDB builders have construction standards that are well above average for production sailboats. The ULDB builders say that their close proximity to each other in Santa Cruz, combined with their open sharing of technology, has enabled them to achieve these high standards. The Olson 30 is no exception. The hull and deck are fiberglass, vacuumbagged over a balsa core. The process of vacuum-bagging insures maximum saturation of the laminate and core with a minimum of resin, making the hull light and stiff. The builder claims that -they have so refined the construction of the Olson 30 that each finished hull weighs within 10 pounds of the standard. The deck of the Olson does not have plywood inserts in place of the balsa where winches are mounted, instead relying on external backing plates for strength.
The hull to deck joint is an inward turned, overlapping flange, glued with a rigid compound called Reid’s adhesive, and mechanically fastened with closely spaced bolts through a slotted aluminum toerail. This provides a strong, protected joint, seaworthy-enough for sailing offshore. The aluminum toerail provides a convenient location for outboard sheet leads, but is painful for those sitting on the rail.
The Olson 30’s 1800-pound keel is deep (5′ 1″ draft) and less than five inches thick. Narrow, bolted-on keels need extra athwartship support. The Olson 30 accomplishes this with nine six-inch bolts, and one ten-inch bolt (to which the lifting eye is attached). The lead keel is faired·with polyester putty and then completely wrapped with fiberglass to seal the putty from the marine environment.
Too many builders neglect sealing autobody putty-faired keels, and too many boat owners then find the putty peeling off at a later date. The Olson’s finished keel is painted, and, on the boats we’ve seen, remarkably fair. The keel-stepped, single-spreader, tapered mast is cleanly rigged with 5/32-inch Navtec rod rigging and internal tangs. The mast section is large enough for peace of mind in heavy air. The halyards exit the mast at well-spaced intervals, to avoid creating a weak spot. The chainplates are securely attached to half-bulkheads of I-inch plywood. In addition, a tie-rod attaches the deck to the mast, tensioned by a turnbuckle. While this arrangement should provide adequate strength, we would prefer both a tie-rod and a full bulkhead that spans the width of the cabin to absorb the compressive loads that rig tension puts on the deck.
The rudder’s construction is labor-intensive but strong. Urethane foam is hand shaped to templates, then glued to a two-inch diameter solid fiberglass rudder post. The builder prefers fiberglass because it has more “memory” than aluminum or steel. Stainless steel straps are wrapped around the rudder and mechanically fastened to the post. Then the whole rudder assembly is faired, fiberglassed, and painted.
PERFORMANCE
Handling Under Sail
For those of you who agonize over whether your PHRF rating is fair, consider the ratings of ULDBs. The Santa Cruz 50 rates 0; that’s right, zero. The 67-foot Merlin has rated as low as minus 60. The Olson 30 rates anywhere from 90 to 114, depending on the local handicapper. Olson 30 owners tell us that the boat will sail to a PHRF rating of 96, but she will almost never sail to her astronomical lOR rating of 32 (the lOR heavily penalizes ULDBs). ULDBs are fast. They are apt to be on the tender side, and sail with a quick, “jerky” motion through waves. Instead of punching through waves, they ride over them. Owners tell us that they do far less cruising and far more racing than they had expected to do when they bought the boat. They say it’s more fun to race because the boat is so lively.
Like most ULDBs, the Olson 30 races best at the extremes of wind conditions-under 10 knots and over 20 knots. Although her masthead rig may appear short, it is more than powerful enough for her displacement. Owners tell us that she accelerates so quickly you can almost tack at will – a real tactical advantage in light air. In winds under 10 knots, they say she sails above her PHRF rating, both upwind and downwind. In moderate breezes it’s a different story. Once the wind gets much above 10 knots, it’s time to change down to the #2 genoa. In 15 knots, especially if the seas are choppy, it’s very difficult for the Olson 30 to save her time on boats of conventional displacement, according to three-time national champ Kevin Connally. The Olson 30 is always faster downwind, but even with a crew of 5 or 6, she just can’t hang in there upwind. In winds above 20 knots, the Olson 30 still has her problems upwind. But when she turns the weather mark the magic begins. As soon as she has enough wind to surf or plane, the Olson 30 can make up for all she looses upwind, and more. The builder claims that she has pegged speedometers at 25 knots in the big swells and strong westerlies off the coast of California. That is, of course, if the crew can keep her 1800-pound keel under her 761-square foot spinnaker. The key to competitiveness in a strong breeze is the ability of the crew. Top crews say that because she is so quick to respond, they have fewer problems handling her in heavy air. However, an inexperienced crew which cannot react quickly enough, can have big problems. “The handicappers say she can fly downwind, so they give us a low (PHRF) rating. But they don’t understand that we have sail slow, just to stay in control,” complained the crew of one new owner.
Like any higher performance class of sailboat, the Olson 30 attracts competent sailors. Hence, the boat is pushed to a higher level of overall performance, and the PHRF rating reflects this. An inexperienced sailor must realize that he may have a tougher time making her sail to this inflated rating than a boat that is less “hot.”
The two most common mistakes that new Olson 30 owners make are pinching upwind and allowing the boat to heel excessively. ULDBs cannot be sailed at the 30 degrees of heel to which many sailors of conventional boats are accustomed. To keep her flat, you must be quick to shorten sail, move the sheet leads outboard, and get more crew weight on the rail. You can’t afford to have a person sitting to leeward trimming the genoa in a 12-knot breeze. To keep her thin keel from stalling upwind, owners tell us it’s important to keep the sheets eased and the boat footing.
Being masthead-rigged, the Olson 30 needs a larger sail inventory than a fractionally rigged boat. Class rules allow one mainsail, six headsails (jibs and spinnakers) and a 75-percent storm jib. Owners who do mostly handicap racing tell us they often carry more than six headsails.
Handling Under Power
Only a few of the Olson 30s sold were equipped with inboard power. This is because the extra weight of the inboard and the drag of the propeller, strut and shaft are a real disadvantage when racing against the majority of Olson 30s, which are equipped with outboard motors. The Olson 30 is just barely light enough to be pushed by a four to five horsepower outboard. It takes a 7.5 horse outboard to push the Olson 30 at 6.5 knots in a flat calm. The Olson’s raked transom requires an extra long outboard bracket, which puts the engine throttle and shift out of reach for anyone much less than 6 feet tall: “A real pain,” said one owner. Storage is a problem, too. Even if you could get the outboard through the stern lazarette’s small hatch, you wouldn’t want to race with the extra weight so far aft. As a result, most owners end up storing the outboard on the cabin sole. The inboard was an optional, 154-pound, 7-horsepower, BMW diesel. Unlike most boats, the Olson 30 will probably never return the investment in an inboard when the boat is sold. It detracts from the boat’s primary purpose-racing.
Without an inboard, owners have a problem charging the battery. Owners who race with extensive electronics have to take the battery ashore after every race for recharging. If the Olson 30 weren’t such a joy to sail in light air, and so maneuverable in tight places, the lack of inboard power would be a serious enough drawback to turn away more sailors than it does.
Deck Layout
In most respects, the Olson 30 is a good sea boat. Although the cockpit is 6-1/2 feet long, the wide seats and narrow floor result in a relatively small cockpit volume, so little sea water can collect in the cockpit if the boat is pooped or knocked down. However, foot room is restricted, while the width of the seats makes it awkward to brace your legs on the leeward seat. The seats themselves
There are gutters to drain water off the leeward seat. The long mainsheet traveler is mounted across the cockpit. The Olson 30’s single companionway dropboard is latchable from inside the cabin, a real necessity in a storm offshore. A man-overboard pole tube in the stern is standard equipment. Teak toerails on the cockpit combing and on the forward part of the cabin house provide good footing, and there are handholds on the after part of the cabin house. The tapered aluminum stanchions are set into sockets molded into the deck and glassed to the inside of the hull, a strong, clean, leak-proof system. However, the stanchions are not glued or mechanically fastened into the sockets. If pulled upwards with great force they can be pulled out. We feel this is a safety hazard. Tight lifelines would help prevent this from happening, but most racing crews tend to leave them slightly loose so they can lean further outboard when hanging over the rail upwind. If the stanchions were fastened into the sockets with bolts or screws they would undoubtedly leak. A leakproof solution to this problem should be devised and made available to Olson 30 owners. The cockpit has two drains of adequate diameter. The bilge pump, a Guzzler 500, is mounted in the cockpit. As is common on most boats, the stern lazarette is not sealed off from the rest of the interior. If the boat were pooped or knocked down with the lazarette open, water could rush below through the lazarette relatively unrestricted. As the Olson 30 has a shallow sump, there is little place for water to go except above the cabin sole. A “paint-roller” type non-skid is molded into the Olson 30’s deck It provides excellent traction, but it is more difficult to keep clean than conventional patterned non-skid.
The Olson 30 is well laid out with hardware of reasonable, but not exceptional, quality. All halyards and pole controls lead to the cockpit through Easylock 1 clutch stoppers. The Easylocks are barely big enough to hold the halyards; they slip an inch under heavy loads. Older Olsons were equipped with Howard Rope Clutches. The Howards had’ a history of breaking (although the manufacturer has now corrected the problem). The primary winches, Barient 22s, are also barely adequate. Some owners we talked to had replaced them with more powerful models. Schaefer headsail track cars are standard equipment. One owner complained that he had to replace them with Merrimans because the Schaefers kept slipping.
Leading the vang to either rail and leading the reefing lines aft is also recommended. The mast partner is snug, leaving no space for mast blocks. The mast step is movable to adjust the prebend of the spar. The partner has a lip, over which a neoprene collar fits. The collar is hose-clamped to the mast. This should make a watertight mast boot. However, on the boat we sailed, the bail to which the boom vang attached obstructed the collar, causing water to collect and drain into the cabin.
The yolked backstay is adjustable from either quarter of the stem, one side being a 2:1 gross adjustment and the other side being an 8:1 fine tune. A Headfoil II is standard equipment. There is a babystay led to a track with a 6:1purchase for easy adjustment. The track is tied to the thin plywood of the forward V -berth with a wire and a turnbuckle. On the boat we sailed, the padeye to which the babystay tie rod is attached was seen to be tearing out from the V-berth.
There is a port in the deck directly over the lifting eye in the bilge. This makes for quick and easy drysailing. The Olson 30, however, is not easily trailered; her 3600 pounds is too much for all but the largest cars, and her 9.3-foot beam requires a special trailering permit.
The Olson 30 is cramped belowdecks. Her low deckhouse and substantial sheer may make her one of the sexiest-looking production boats on the water, but the price is headroom of only four feet, five inches. There is not even enough headroom for comfortable stooping. Moving about below is a real grind for an average-sized person. To offset the confinement of the interior, the builder has done everything possible to make it light and airy. In addition to the Lexan forward hatch and cabin house windows, the companionway hatch also has a Lexan insert. The inside of the hull is smooth sanded and finished with white gelcoat. There are no full-height bulkheads dividing the cabin. All the furniture is built of lightweight, light-colored, 3/8″ Scandanavian, seven-ply plywood.
The joinerwork is above average and all of the bulkhead and furniture tabbing is extremely neat. There isn’t much to the Olson 30’s interior, but what there is has been done with commendable craftmanship. The cabin sole is narrow, and with the lack of headroom, the woodwork is susceptible to being dinged and scratched from equipment like outboard motors. Once the finish on the wood is broken, it quickly absorbs water, which collects in the shallow bilge. ‘
The Olson 30 is not a comfortable cruiser. Even after you’ve taken all the racing sails ashore, the belowdecks is barely habitable. To save weight the quarterberths are made of thin cushions sewn to vinyl and hung from pipes.These pipe berths are comfortable, but the cushions are not easily removed. Should they get wet it’s likely they would stay wet for some time. Two seabags are hung on sail tracks above the quarter berths, which should help to insure that some clothes stay dry.
Just forward of each quarterberth is a small uncushioned seat locker. Behind each seat is a small portable ice cooler. In one seat locker is the stove, an Origo 3000, which slides up and out of the locker on tracks. The Ongo is a top-of-theline unpressurized alcohol stove, but to operate it the cook must kneel on the cabin sole. To work at the navigation station, which is in front of the starboard seat, you must sit sideways. In front of the port seat is the lavette, with a hand water pump and a removable, shallow, drainless sink. Drainless sinks eliminate the need for a through-hull fitting-a good idea-but they should be deep, not shallow.
Although there are curtains which can be drawn across the V-berth, we think human dignity deserves an enclosed head, especially on a 30’ boat. The V-berth is large and easy to climb into, but there are no shelves above it or a storage locker in the empty bow. In short, if you plan to cruise for more than a weekend, you’d better like roughing it.
CONCLUSIONS
A completely equipped Olson 30 ran about $35,000. Today, a used one will cost from $24,000 to $28,000 ( note – this was written in 1987, prices are lower in 2015 ). What do you get for this? You get a boat that’s well built, seaworthy, and reasonably well laid out. You get a boat that, in light air, will sail as fast as boats costing nearly twice as much. Downwind in heavy air, you have a creature that will blow your mind and leave everything (except a bigger ULDB) in your wake. If you spend all of your sailing time racing in a PHRF fleet in an area where light or heavy air dominates, the Olson 30 will probably give you more pleasure for your dollar than almost anything afloat.
However, if you race in moderate air or enjoy more than an occasional short cruise, you are likely to be very disappointed. Before you consider the Olson 30, you must realistically evaluate your abilities as a sailor. There’s nothing worse, after finding out that you can’t race a boat to her potential, than realizing that she is of little use for any other aspect of our sport.
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Dear Readers
- Sailboat Reviews
This speedster is as specialized as it gets; mind-blowing performance, but almost no living space.
The Olson 30 is of a breed of sailboats born in Santa Cruz, California called the ULDB , an acronym for ultra light displacement boat. ULDBs are big dinghies—long on the waterline, short on the interior, narrow on the beam, and very light on both the displacement and the price tag. ULDBs attract a different kind of sailor—the type for whom performance means everything.
For some yachting traditionalists, the arrival of ULDB has been a hard pill to swallow. Part of this is simple resentment of a ULDB’s ability to sail boat for-boat with a racer-cruiser up to 15′ longer (and a whole lot more expensive). Part of it is the realization that, to sail a ULDB might mean having to learn a whole new set of sailing skills. Part of it is a reaction to the near-manic enthusiasts of Santa Cruz, where nearly 100 ULDBs race for pure fun—without the help of race committees, protest committees, or handicaps (in Santa Cruz, IOR is a dirty word). And part of the traditionalists’ resentment is their gut feeling that ULDBs aren’t real yachts.
In 1970, Californian George Olson tried an experiment and created the first ULDB. He thought if he took a boat with the same displacement and sail area as a Cal 20, but made it longer and narrower, it might go faster. The boat he built was called Grendel and it did go faster than a Cal 20, much faster than anyone had expected. The plug for Grendel was later widened by Santa Cruz boatbuilder Ran Moors, and used to make the mold for the Moore 24, a now-popular ULDB one-design.
In the meantime, George Olson had joined up with another Santa Cruz builder by the name of Bill Lee, and together they designed and built the Santa Cruz 27. Olson also helped Lee build his 1977 Transpac winner Merlin, a 67′, 20,000 pound monster of a ULDB (she was subsequently legislated out of theTranspac race). Then Olson and several other of Lee’s employees started their own boatbuilding firm (in Santa Cruz, of course) called Pacific Boats. The first project for Pacific Boats was the Olson 30, which was put into production in 1978. Pacific Boats later became Olson/Ericson, and produced a 25 and a 40. The latest incarnation of the 30 is called the 911.
Construction
Some people wonder how ULDBs can be built so light, yet still be seaworthy offshore. The answer is three-fold: first, a light boat is subjected to lighter loads, when pounding through a heavy sea, than a boat of greater displacement. Second, there is a tremendous saving in weight with a stripped-out interior. Third, as a whole, ULDB builders have construction standards that are well above average for production sailboats. The ULDB builders say that their close proximity to each other in Santa Cruz combined with an open sharing of technology has enabled them to achieve these standards.
The Olson 30 is no exception. The hull and deck are fiberglass vacuum-bagged over a balsa core. The process of vacuum-bagging insures maximum saturation of the laminate and core with a minimum of resin, making the hull light and stiff. The builder claims that they have so refined the construction of the Olson 30 that each finished hull weighs within 10 pounds of the standard. The deck of the Olson does not have plywood inserts in place of the balsa where winches are mounted, instead relying on external backing plates for strength.
The hull-to-deck joint is an inward turned overlapping flange, glued with a rigid compound called Reid’s adhesive, and mechanically fastened with closely spaced bolts through a slotted aluminum toerail. This provides a strong, protected joint, seaworthy enough for sailing offshore. We would prefer a semi-rigid adhesive, however, because it is less likely to fracture and cause a leak in the event of a hard collision. The aluminum toerail provides a convenient location for outboard sheet leads, but is painful to those sitting on the rail.
The Olson 30’s 1,800 pound keel is deep (5.1′ draft) and less than 5″ thick. Narrow, bolted-on keels need extra athwartships support. The Olson 30 accomplishes this with nine 5/8″ bolts and one 1″ bolt (to which the lifting eye is attached). The lead keel is faired with auto body putty and then completely wrapped with fiberglass to seal the putty from the marine environment. Too many builders neglect sealing auto body putty-faired keels, and too many boat owners then find the putty peeling off at a later date. The Olson’s finished keel is painted, and, on the boats we have seen, remarkably fair.
The keel-stepped, single-spreader, tapered mast is cleanly rigged with 5/32″ Navtec rod rigging and internal tangs. The mast section is big enough for peace of mind in heavy air. The halyards exit the mast at well-spaced intervals, so as not to create a weak spot.The shroud chainplates are securely attached to half-bulkheads of 1″ plywood. In addition, a tie rod attaches the deck to the mast, tensioned by a turnbuckle. While this arrangement should provide adequate strength, we would prefer both a tie rod and a full bulkhead that spans the width of the cabin so as to absorb the compressive loads that the tension of the rig puts on the deck.
The rudder’s construction is labor intensive, but strong. Urethane foam is hand shaped to templates, then glued to a 4″ thick solid fiberglass rudder post. The builder prefers fiberglass because it has more “memory” than aluminum or steel. Stainless steel straps are wrapped around the rudder and mechanically fastened to the post. Then the whole assembly is faired, fiberglassed, and painted.
Handling Under Sail
For those of you who agonize over whether your PHRF rating is fair, consider the ratings of ULDBs. The Santa Cruz 50 rates 0; that’s right— zero . The 67′ Merlin has rated as low as minus 60. The Olson 30 rates anywhere from 90 to 114, depending on the local handicapper. Olson 30 owners tell us that the boat will sail to a PHRF rating of 96, but she will almost never sail to her astronomical IOR rating of 32′ (the IOR heavily penalizes ULDBs).
ULDBs are fast. They are apt to be on the tender side, and sail with a quick, “jerky” motion through waves. Instead of punching through a wave, they ride over it. You may get to where you are going fast, but with the motion of the boat and the Spartan interior you won’t get there in comfort. Olson 30 owners tell us that they do far less cruising and far more racing that they had expected to do when they bought the boat. They say it’s more fun to race because the boat is so lively.
Like most ULDBs the Olson 30 races best at the extremes of wind conditions—under 10 knots and over 20 knots. Although her masthead rig may appear short, it is more than powerful enough for her displacement. Owners tell us that she accelerates so quickly you can almost tack at will—a real tactical advantage in light air. In winds under 10 knots they say she sails above her PHRF rating both upwind and downwind.
In moderate breezes it’s a different story. Once the wind gets much above 10 knots, it’s time to change down to the #2 genoa. In 15 knots, especially if the seas are choppy, it’s very difficult for the Olson 30 to save her time on boats of conventional displacement, according to three-time national champ Kevin Connally. The Olson 30 is always faster downwind, but even with a crew of 5 or 6, she just cannot hang in there upwind.
In winds above 20 knots, the Olson 30 still has her problems upwind, but when she turns the weather mark the magic begins. As soon as she has enough wind to either surf or plane, the Olson 30 can make up for all she loses upwind, and more. The builder claims that she has pegged speedometers at 25 knots in the big swells and strong westerlies off the coast of California. That is, if the crew can keep her 1800 pound keel under her 761 sq. ft. spinnaker.
The key to competitiveness in a strong breeze is the ability of the crew. Top crews say that, because she is so quick to respond, they have fewer problems handling her in heavy air than a heavier, conventional boat. However, an inexperienced crew which cannot react fast enough can have big problems. “The handicappers say she can fly downwind, so they give us a low rating (PHRF), but they don’t understand that we have to sail slow just to stay in control,” complained the crew of one new owner.
Like any higher performance class of sailboat, the Olson 30 attracts competent sailors. Hence, the boat is pushed to a higher level of overall performance, and the PHRF rating reflects this. An inexperienced sailor must realize that he may have a tougher time making her sail to this inflated rating than a boat that is less “hot.” The two most common mistakes that new Olson 30 owners make are pinching upwind and allowing the boat to heel excessively. ULDBs cannot be sailed at the 30 degrees of heel to which many sailors of conventional boats are accustomed. To keep her flat you must be quick to shorten sail, move the sheet leads outboard, and get more crew weight on the rail. You can’t afford to have a person sitting to leeward trimming the genoa in a 12-knot breeze. To keep her thin keel from stalling upwind, owners tell us it’s important to keep the sheets eased and the boat footing.
Being masthead-rigged, the Olson 30 needs a larger sail inventory than a fractionally rigged boat. Class rules allow one mainsail, six headsails (jibs and spinnakers) and a 75% storm jib. Owners who do mostly handicap racing tell us they often carry more than six headsails.
Handling Under Power
Only a few of the Olson 30s sold to date have been equipped with inboard power. This is because the extra weight of the inboard and the drag of the propeller, strut and shaft are a real disadvantage when racing against the majority of Olson 30s, which are equipped with outboard engines. The Olson 30 is just barely light enough to be pushed by a 4-5 hp outboard, which is the largest outboard that even the most healthy sailor should be hefting over a transom. It takes a 7.5 hp. outboard to push the Olson 30 at 6.5 knots in a flat calm. The Olson’s raked transom requires an extra long outboard bracket, which puts the engine throttle and shift out of reach for anyone much less than 6′ tall: “A real pain in the ass,” said one owner. Storage is a problem, too. Even if you could get the outboard through the stern lazarette’s small hatch, you wouldn’t want to race with the extra weight so far aft. So most owners end up storing the outboard on the cabin sole.
The inboard, a 154 pound, 7 hp BMW diesel, was a $4,500 option. Unlike most boats, the Olson 30 will probably not return the investment in an inboard when you sell the boat, because it detracts from the boat’s primary purpose—racing.
Without an inboard there’s a problem charging the battery. Owners who race with extensive electronics have to take the battery ashore after every race for recharging. If the Olson 30 weren’t such a joy to sail in light air, and so maneuverable in tight places, the lack of inboard power would be a serious enough drawback to turn away more sailors than it does.
Deck Layout
In most respects, the Olson 30 is a good sea boat. Although the cockpit is 6 1/2′ long, the wide seats and narrow floor result in a relatively small cockpit volume, so that little sea water can collect in the cockpit if the boat is pooped or knocked down. However, foot room is restricted, while the width of the seats makes it awkward to brace your legs on the leeward seat. The seats themselves are comfortable because they are angled up and the seatbacks are angled back. There are gutters to drain water off the leeward seat. The long mainsheet traveler is mounted across the cockpit—good for racing but not so good for cruising.
The Olson 30’s single companionway drop board is latchable from inside the cabin, a real necessity in a storm offshore. A man overboard pole tube in the stern is standard equipment. Teak toerails on the cockpit coaming and on the forward part of the cabin house provide good footing, and there are handholds on the aft part of the cabin house.
The tapered aluminum stanchions are set into sockets molded into the deck and glassed to the inside of the hull, a strong, clean, leak-proof system. However, the stanchions are not glued or mechanically fastened into the sockets. If pulled upwards with great force they can be pulled out. We feel this is a safety hazard. Tight lifelines would help prevent this from happening, but most racing crews tend to leave them slightly loose so as to be able to lean farther outboard when hanging over the rail upwind. If the stanchions were fastened into the sockets with bolts or screws they would undoubtedly leak. A leakproof solution to this problem should be devised and made available to Olson 30 owners.
The cockpit has two drains of adequate diameter.
The bilge pump, a Guzzler 500, is mounted in the cockpit. The Guzzler is an easily operated, high capacity pump. However, its seeming fragility worries us. As is common on most boats, the stern lazarette is not sealed off from the rest of the interior. If the boat were pooped or knocked down with the lazarette open, water could rush below through the lazarette relatively unrestricted. As the Olson 30 has a shallow sump, there is little place for water to go except above the cabin sole.
A “paint-roller” type non-skid is molded into the Olson 30’s deck. It provides excellent traction, but it is more difficult to keep clean than conventional patterned non-skid.
The Olson 30 is well laid out with hardware of reasonable, but not exceptional, quality. All halyards and pole controls lead to the cockpit though Easylock I clutch stoppers. The Easylocks are barely big enough to hold the halyards; they slip an inch under heavy loads. Older Olsons were equipped with Howard Rope Clutches.
The primary winches, Barient 22s, are also barely adequate. Some owners we talked to had replaced them with more powerful models. Schaefer headsail track cars are tandard equipment. One owner complained that he had to replace them with Merrimans because the Schaefers kept slipping. Leading the vang to either rail and leading the reefs aft is also recommended. The mast partner is snug, leaving no space for mast blocks. The mast step is movable to adjust the prebend of the spar. The partner has a lip, over which a neoprene collar fits. The collar is hoseclamped to the mast. This should make a watertight mast boot. However, on the boat we sailed, the bail to which the boom vang attached obstructed the collar, causing water to collect and pour into the cabin.
The yoked backstay is adjustable from either quarter of the stern, one side being a 2-to-1 gross adjustment and the other side being an 8-to-1 fine tune. A Headfoil II is standard equipment. There is a babystay led to a ball-bearing track with a 4-to-1 purchase for easy adjustment. The track is tied to the thin plywood of the forward V-berth with a wire and turnbuckle. On the boat we sailed, the pad eye to which the babystay tie rod is attached was tearing out of the V-berth.
There is a port in the deck directly over the lifting eye in the bilge. This makes for quick and easy drysailing. The Olson 30, however, is not easily trailered; her 3600 pounds is too much for all but the largest cars, and her 9.3′ beam requires a special trailering permit.
The Olson 30 is cramped belowdecks. Her low freeboard, short cabin house and substantial sheer may make her the sexiest-looking production boat on the water, but the price is headroom of only 4′ 5″. There is not even enough headroom for comfortable stooping; moving about below is a real chore.
To offset the confinement of the interior, the builder has done all that is possible to make it light and airy. In addition to the lexan forward hatch and cabin house windows, the companionway hatch also has a lexan insert. The inside of the hull is smoothly sanded and finished with white gelcoat. There are no full height bulkheads dividing up the cabin. All of the furniture is built of lightweight, light-colored, 3/8″ thick Scandinavian plywood of seven veneers.
The joinerwork is above average and all of the bulkhead and furniture tabbing is extremely neat. There isn’t much to the Olson 30’s interior, but what there is has been done with commendable craftsmanship. The interior wood is fragile, though. There are several unsupported panels of the 3/8″ plywood; if someone were to fall against them with much force it’s likely they would fracture. The cabin sole is narrow, and with the lack of headroom the woodwork is especially susceptible to being dinged and scratched from equipment like outboard engines. Once the finish on the wood is broken, it quickly absorbs water, which collects in the shallow bilge.
The Olson 30 is not a comfortable cruiser. Even after you’ve taken all the racing sails ashore, the belowdecks is barely habitable. To save weight the quarterberths are made of thin cushions sewn to vinyl and hung from pipes. These pipe berths are comfortable, but the cushions are not easily removed. Should they get wet it’s likely they would stay wet for quite a while. Two seabags are hung on sail tracks above the quarter berths, which should help to insure that some clothes always stay dry.
Just forward of each quarterberth is a small uncushioned seat locker. Behind each seat is a small portable ice cooler. In one seat locker is the stove, an Origo 3000 which slides up and out of the locker on tracks. The Origo is a top-of-the-line unpressurized alcohol stove, but to operate it the cook must kneel on the cabin sole. To work at the navigation station, which is in front of the starboard seat, you must sit sideways. In front of the port seat is the lavette, with a hand water pump and a removable, shallow drainless sink. Drainless sinks eliminate the need for a through-hull fitting, a good idea; but they should be deep, not shallow.
The portable head is mounted under the forward V-berth, which we think is totally unsuitable for a sailboat. Who wants a smelly toilet under his pillow? Although there are curtains which can be drawn across the V-berth, we think human dignity deserves an enclosed head, especially on a 30′ boat. The Vberth is large and easy to climb into, but there are no shelves above it nor a storage locker in the empty bow. In short, if you plan to cruise for more than a weekend you had better like roughing it.
Conclusions
For 30-footers, the price of an Olson 30 is cheap; but for boats of similar displacement, it’s damned expensive.
What do you get for the money? You get a boat that is well-built, seaworthy, and reasonably well laid out. You get a boat that, in light air, will sail as fast as boats costing nearly twice as much. Downwind in heavy air, you have a creature that will blow your mind and leave everything shy of a bigger ULDB in your wake. If you spend all of your sailing time racing in a PHRF fleet in an area where light or heavy air dominates, the Olson 30 will probably give you more pleasure for your dollar than almost anything afloat.
However if you race often in moderate air or enjoy more than a very occasional short cruise, you are likely to be very disappointed. Before you consider the Olson 30, you must realistically evaluate your abilities as a sailor. There’s nothing worse than, after finding out that you can’t race a boat to her potential, knowing that she is of little use for the other aspects of our sport.
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A Complete Guide to Displacement Hulls (Illustrated)
The displacement hull is the classic go-to hull design for sailboats and one of the most recognizable ones out there. In this guide, I explain all there is to know about them.
What's a displacement hull? A displacement hull is a boat hull design that uses buoyancy to support its weight. It lies partially submerged and displaces water when moving, hence its name. The amount of water it displaces is equal to its weight. It's very stable in rough waters. That's why this design is widely used on cruisers and sailboats.
Displacement hulls are great and reliable. Below we'll talk all about that. But they all have one major setback. Read on to find out what.
On this page:
Displacement hull features, how a displacement hull actually works, why it's so fuel-efficient, setback: maximum hull speed, advantages & disadvantages of displacement hulls, who might like this type of hull, in conclusion.
Nearly all sailboats have displacement hulls. Displacement hulls are great for operating in rough waters. They are less affected by waves than planing hulls. Because they're so steady, they are to go-to design for many ocean-going boats. Examples of boats with displacement hulls are: sailboats, canoes, and fishing boats and trawlers.
The displacement hull is:
- the most reliable & efficient hull in rough water
- the most fuel-efficient hull
- the most buoyant hull
- the hull with the largest cargo capacity
I'll explain all these points later on, but first, I want to just describe the hull design for you.
Design Features
Displacement hulls are pretty bulky. They have round bilges. The bilge is where the boat's bottom curve meets its vertical sides. The hull itself is round. It's round because that creates less resistance when moving through the water. That roundness is what makes it such a comfortable ride, even in waves.
But that roundness also makes it easy to roll (think of canoes, for example). That's not a good feature in heavy weather. To offset it, sailboats have a heavy keel that runs deep into the water. This counterbalances any roll, making the boat very stable. Sailboats with a long keel are very difficult to capsize.
The hull is rounded throughout, running from bow (front) to aft (back).
The displacement hull is generally pretty heavy. That's okay, since it is supported by its buoyancy, so it doesn't need a lot of power to propel (more on this later). The weight actually helps it be more stable and unbothered by nature's pull. I think it's fair to call the displacement hull with the whale among boats . It uses the water's upforce to carry it, and gently peddles along.
How Fast Is It?
Since this hull needs to move a lot of water before going anywhere, displacement hulls are pretty slow. Actually, it very well may be the slowest hull type out there. On average, their cruising speed lies anywhere between 6 - 8 knots. They can go faster, but most boats with displacement hulls don't have the power to do so.
They are great at low speeds. Thanks to their shape, they are easy to move and don't require a lot of power. They're actually one of the most fuel-efficient designs out there.
Compared to other hull types:
- Displacement Hull - Partially submerged, buoyant, moves water
- Planing Hull - Glides over water surfaces, generates lift |
- Semi-Displacement Hull - Displaces at low speed, lifts partially at cruising speed
I've written an Illustrated Guide to Boat Hull Types , where I go over 11 different examples of the most common boat hulls . That article will give a great and quick overview to get you up to speed, so if you don't know anything about boat hulls yet, that article is a great place to start.
The shape of the hull creates a sort of air bubble that floats on top of the water. At the same time, the weight of the boat pushes down (or actually, gravity pulls it down). This submerges the boat a bit, anchoring it, in a way. This push-pull gives it its characteristic reliability, making it more stable and better at keeping course.
As with anything that is really good at floating, it doesn't require a lot of energy to propel it. Since it can use the water to carry it, it's great for carrying cargo. You can really load her up without drastically increasing fuel consumption.
A planing hull needs to get up to speed before it generates lift, and until it does, it's absolutely rubbish in terms of a smooth ride. That's why planing hulls can get so uncomfortable in waves. They can't get up to speed, and their hull isn't made for displacing - rather flying - so it becomes a terrible ride.
The one major setback for displacement hulls is the upper-speed limit. As I've noted before, they are pretty slow. But the thing is: they can't go beyond their upper-speed limit, even if you gear her up with massive outboard engines and so on. The reason for this is called the maximum hull speed .
To understand the maximum hull speed and how it works, I want you to think of yourself lying in the Mediterranean Sea. That's just arbitrary, but since I can pick any sea I like in these kinds of visualizations, I prefer the Mediterranean. So you're lying in the Meds and along comes a sailboat. The sailboat hauls a rope behind it (I know, a line). You grab on to the rope and hold tight. The sailboat gently drags you along. It accelerates. The pull increases, you have to grab on even tighter. It accelerates even more. You have to really clench now.
The reason you have to increase your grip when the sailboat accelerates is simple. Your body displaces water when you move. When the speed increases, it has to displace the same amount of water, but faster. The water resistance (drag) increases.
The power needed to displace water increases exponentially with speed.
So now you can probably imagine that there will be a point where you can no longer hold on and have to let go. You have to slow down. That's your maximum hull speed working.
In the same way, there's a point where the boat's drag becomes so large, that it becomes almost impossible to propel it, no matter the amount of power. That speed is called the maximum hull speed. Every displacement hull has one, and it is a direct correlation with the boat's length. If you want to check out the maximum hull speeds for different boat lengths and learn how to easily calculate it yourself, you can check out a previous article. In it, I go over average sailboat speeds and the formula for calculating maximum hull speed .
By the way, the reason planing hulls can go faster, is that they generate lift at a certain speed. In terms of our story just now, that's the same as if you got yourself a wakeboard. Then, when the boat accelerates, at one point you pull yourself out of the water, and glide over the surface, instead of lying in it.
As with anything, this design has both pros and cons. I'll go over each one briefly down below.
- handle well in rough waters
- very hard to sink
- smooth ride
- large cargo capacity
- requires little power: very efficient
- very dependable
- can be very heavy
- large range
Disadvantages
- has a maximum hull speed
- tends to roll
- can capsize if it has no keel
- if it does have a keel, it has a deep draft
If you don't care about speed and are all about range, safety or comfort, the displacement hull is the way to go. It's by far the most comfortable ride of all hull types and will get you anywhere. You can cross oceans, cruise inland - it doesn't really matter. It has the largest range of all the hull types, and the fuel-economy is really impressive. With cruising speeds averaging between 6 - 8 knots, this hull type is the slowest, but also the steadiest. The perfect boat for long-range cruisers and liveaboards.
Displacement hulls have been around for centuries, and they are the most well-known hull for a reason. They're reliable and efficient. Those are perhaps the two most important trades when you're at sea. Nearly all sailboats have displacement hulls, and for cruising, the benefits outweigh the drawbacks big time. If you like speed, however, you should consider getting something with a planing hull or semi-displacement hull. You can learn everything about semi-displacement hulls here .
Jacques Burgalat
Great tutorial ! Do you know of anyone (or company) who could help me with using a fully electric power train on a 19m/40 ton Tjalk? I (and the tjalk) are currently on the Saint Johns River (Florida) which is more akin to a lake or canal than an actual “river”, so fighting waves and currents is not an issue.
Thank you for your help.
Leave a comment
You may also like, the illustrated guide to boat hull types (11 examples).
I didn't understand anything about boat hull types. So I've researched what hulls I need for different conditions. Here's a complete list of the most common hulls.
Semi-Displacement Hulls Explained (Illustrated Guide)
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PHRF Racing: Choosing a Boat
- By Bruce Bingman
- Updated: September 18, 2013
Many factors go into buying a sailboat, including price, availability, style, and how much the boat will be used off the racecourse. At the risk of adding another facet to an already complicated decision, we tasked PHRF guru Bruce Bingman with identifying a few boats that are likely to sail above their rating in certain conditions. As is the case with any single-number rating system, every boat will have a sweet spot, a combination of wind strength, sea state, and course configuration under which it will be tough to beat.
For this exercise we asked Bingman to focus on boats that would be predominantly raced in club-level weeknight or weekend races. We wanted boats that are lively, fun to sail, and available. In addition, we restricted him to boats with an average PHRF rating of 30 or greater. Below that number you tend to find dry-sailed race boats requiring professionally managed programs, which are beyond the scope of this exercise, and usually too fast to really race in most local series.
It goes without saying that for any even halfway serious racing, preparation is as important as the boat selected or the handicap rating with which it comes. We’ve all heard it 1,000 times before: There is no substitute for good sails, reliable gear, and a smooth bottom. You may think your two- or three-year-old sails look fine, but you will pick up 6 seconds per mile and more with a new inventory. The most carefully selected boat or the most favorable rating won’t help you overcome a mid-race breakdown such as a broken halyard or jammed winch. A dirty bottom can cost you 30-plus seconds per mile. Even a thin layer of slime will cost you 3 seconds per mile. So pick your weapon, gear up, burnish your bottom, and head for the start.
- Typical conditions: Waves and chop, strong but fading sea breeze
- **Typical racecourses: Multiple lap windward-leewards **
My summer weeknight beercan series is conducted outside the harbor, on an exposed ocean racecourse, so it’s usually choppy. Winds are typically strong sea breezes (15-plus knots) at the start of the race, but lighten as the race progresses. The race committee typically runs one long, three-leg, windward-leeward race.
Here’s where you want the dependable offshore workhorse, and there are many options. A moderate displacement boat, a powerful rig, and a sea-kindly hull will produce a boat that drives upwind, through chop, and carries a spinnaker large enough to preserve a lead.
PHRF 30 to 70: The Beneteau 40.7 is a great offshore racer that provides superior upwind ability in choppy, breezy conditions. Great for a distance races, too.
PHRF 71 to 114: The Beneteau 42s has power and waterline rolled together in a single package. The sails are big, so it requires recruiting some young bucks to help get around the course.
PHRF 115 and up: The Cal 40 is a classic design with the ability to go up and down the course in any condition.
- ** Typical conditions: Flat water, shifty winds can be strong or light**
- Typical racecourses: Mix of random leg and windward-leeward
My local weeknight beercan series is conducted on a sheltered, narrow lake, with very shifty winds, but no current. Winds tend to be at either end of the spectrum: It’s either drifter light or wipeout windy. Because of the prevailing direction and narrowness of the lake, there’s usually a lot of maneuvers on the random-leg courses.
In this scenario we’re looking for light boats that are on the smaller end of the size range for each of the rating bands, but still retain the ability to perform in breezier conditions.
PHRF 30 to 70: Although the Henderson 30 can be a handful in bigger breeze, it’s an excellent light-air performer and reaches like a bandit.
PHRF 71 to 114: The Antrim 27 is a very fast and fun light-air performer that’s great in a breeze, so long as there’s not a lot of chop.
PHRF 115 and up: The B-25 , Leif Bailey’s original sporty speedster, is almost unbeatable under these conditions. An excellent, all-around performer that’s easy to drive around the course, and can still be found at reasonable prices.
- ** Typical conditions: Flat water, moderate winds**
- Typical racecourses: Random legs, all points of sail
My weeknight series is conducted in protected bay waters, with an average current of .5 to 1 knot, and generally flat water (with some chop at the upper wind range). Winds in the summer average 10 to 15 knots, and the organizing committee will typically run courses using government marks, requiring a mix of sailing angles.
In this scenario we want a boat with good all-around performance, especially for headsail reaches, a point of sail where many modern boats with non-overlapping headsails struggle. The 10- to 15-knot wind range is plenty to power most boats, so a very light boat, carrying a penalty for high sail-area-to-displacement ratio, will be at a disadvantage. This is particularly true in a “waterline” race, where a higher hull speed trumps maneuverability. On the other hand, a moderately light displacement boat with not too much wetted surface will ensure you’re not left out in the cold should the wind go light.
PHRF 30 to 70: The J/120 has consistently demonstrated excellent all-around performance to its typical rating.
PHRF 71 to 114: Either the Frers 41 or the J/29 masthead outboard. Both of these boats have overlapping headsails and enough power to get around the course and through the reaches. Which one is best would be dictated by local class splits. It’s generally desirable to be toward the faster end of the class.
PHRF 115 and up: The S2 9.1 was a MORC slayer in its heyday. It’s a very fast, but comfortable, 30-footer with a powerful overlapping headsail and long waterline.
- Typical conditions: Steep chop, moderate winds
- ** Typical racecourses: Windward-leeward**
The races in my weeknight series are held on open, exposed, and typically choppy water, especially in moderate winds. The summer average is 10 knots, and the race committee usually runs windward-leeward courses.
Windward-leeward races are typically won upwind and lost downwind. In this scenario we’re looking for boats that will have good light-air performance to weather while retaining the advantage downwind. We also want to look for boats with relatively fine bow sections to get through the chop.
PHRF 30 to 70: The Farr 30 is still one of the best small windward-leeward boats ever designed (owner bias aside). It’s light and easily driven, but has a fine bow that can cut through the chop when needed. Thanks to the masthead spinnaker, it excels downwind in all breezes.
PHRF 71 to 114: The J/35 has excellent all-around traits. This workhorse provides great performance in the medium breeze, and the overlapping headsail really helps drive through the chop.
PHRF 115 and up: The C&C 35 MK I is often overlooked. With its low wetted surface, overlapping headsail, and narrow beam, it’s an excellent performer, particularly in the chop. The Mark III model, which has a deeper keel and more modern rudder design, is a strong windward performer, but pays in the rating game and is typically a good deal more costly.
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Many people believe that ballast is stability, while in fact it is the center of total weight and the hull form together which are the key factors. Ballast is a way of lowering the center of weight while adversely affecting the hull form. It is possible to get very good stability without ballast; just ask any multihull owner. Ballast really becomes effective at high angles of heel whereas hull form (as in a multihull) is effective at low angles of heel. The interplay of ballast and form stability is the compromise every Architect has to make in designing a boat. Heavily ballasted boats tend to sail at high angles of heel because of their poor form stability. This is caused by the slack bilges and deep sections needed to get the required displacement to carry all that ballast. Less ballasted boats do not require as much volume under water, so their New U.L.D.B. hulls are shallower. The shallower hull has more stability at low angles of heel and is more comfortable to sail. The trick in any design is to get good initial stability from the hull form while using enough ballast to give adequate range of stability for safety. I once read an article by an Architect of repute that stated that anything over 30% ballast ratio was a waste of time. He went on to point out that as you increase your ballast ratio you devastate the hull shape. You do increase the ability of the boat to carry sail, but at a higher angle of heel. What is more, the distorted, heavier hull form has more resistance. Preliminary work carried out by my company, Bray Yacht Design And Research Ltd., has indicated resistance goes up twice as fast as sail carrying ability. Still, ballast ratios have continued to go up. Let us have a look at the effects ballast ratios have on displacement. Using "Jennifer" which was designed for Cruising World's design competition, let us try 50% ballast, and then 25% ballast. The design originally has a conservative ballast ratio of 37%. Jennifer's displacement is 11,500 lbs. of which 4000 lbs. is ballast. To get a 50% ballast ratio the displacement needs to go up to 16,000 lbs., with 8000 lbs. of ballast. Quite a jump in displacement and double the ballast to gain an extra 13%. Its a vicious circle. More ballast means more weight so more ballast is required to get that 50%. We cannot simply add 2000 lbs. to the original 4000 lbs. because that pushes up the displacement too.
50% of 11,500 lbs. = 5750 lbs. So 2000 lbs. additional to 4000 lbs. of existing ballast = 6000 lbs. of ballast. 7500 lbs. of original boat + 6000 lbs. of ballast = 13,500 lbs., but 6000 lbs. of ballast is not 50% of 13,500 lbs. What is more, a larger motor will be needed as well as larger spars, more sail, etc. All this is more weight. More weight means more ballast and so on. But if we deduct 1500 lbs. from the original 4000 lbs. of ballast that gives us 2500 lbs. of ballast on 10,000 lbs. of displacement, a 25% ballast ratio.
The lower ballast ratio means almost 1/4 the weight in ballast, a saving of 5,500 lbs., a much greater saving than canvas pipe berths or inadequate structure. But what happens to the stability you may ask? The stability curves show you clearly. The character of the curve is the same, the range of stability is the same, only the amount of power is different. This means the lightly ballasted New U.L.D.B. boat is not able to carry as much sail but then it does not require as much sail as it is a lighter boat. The smaller sailplan is easier to handle and less expensive. This indicates to me that many of today's designs are headed 180 degrees in the wrong direction, in the name of tradition. In fact traditional working sail ships used very little, if any, permanent ballast. Ships such as the tea clippers were the first vessels to use permanent ballast as a regular part of their design. Ballast ratios varied between 8 and 14% with temporary trim ballast used in small amounts to trim the vessel or set the vessel down to it's lines when sailing unloaded. Otherwise cargo was the main ballast carried. It is my contention that ballast in yachts was introduced by the builders as a trimming ballast to lower the yacht to it's lines. Remember in those days there were few Naval Architects and no one specialized in yacht design. Most commercial ships were built from a half model carved by the shipwright. If a ship showed a good turn of speed or good load carrying ability then sister ships were built. If a client wanted a yacht he chose from a host of commercial designs. Even when yachting became more of a regular thing it was still the commercial architects who designed the yachts, using the same heavy displacement hull forms they were familiar with. At launching time, once a vessel was fitted with its luxurious appointments then it could be ballasted to its lines. From then on it has become common practice to allow as much as 50% for ballasting after all equipment has been accounted for in the design. As a yacht designer, I think pleasure craft should be attacked at a new angle. Cruising and racing yachts carry a vary narrow and predictable range of payload weight. Whereas a 50 foot commercial ship could change draft 3 or 4 feet between empty and loaded, yachts change less than 6 inches. In yachts it is therefore very easy to predict the sailing waterline and characteristics. It is also just as easy to calculate the weight of the completed vessel and work out a hull shape which will give the desired stability. Because commercial ships vary their draft over such a range and because they are beasts of burden their hull shape usually approximates a rectangle with some consideration (but not a lot) being given to resistance. With this hull form not only can the most amount of weight be carried but the best stability characteristics can be maintained throughout the range of draft. It certainly would not do any Architect credit to have a vessel of his design capsize at the dock while being loaded, although it does happen. So what I am saying is that pleasure craft do not need to resemble commercial craft in hull form as their two functions are entirely different. In my research to evaluate this ballast/stability question I have reassessed my thoughts on form stability and how to get a wider range of stability from the hull. This has lead me to a hull shape which is not revolutionary to the eye, but is in the purest of technical sense. In essence I have looked at the hull forms of trimarans and racing scows to create a hull form which will give me stability equivalent to existing vessels without all the dead weight. Not that this hull form can not be used with ballast, but just that heavy displacement distorts it to the point where it becomes less effective. The lighter the displacement the more effectively it works. I have used this hull form to varying degrees in all my designs including the 'Jennifer' and have found it to always yield the same effect. In sailing the one design 'Bray 7.5' we have found that the boat rolls less in a chop, has good stability, very good interior space, and excellent speed. The Bray 7.5 weighs 2300 lbs. complete as a racer/cruiser including spar, galley, head, four good size berths and an outboard. A 7 h.p. outboard pushes the B7.5 to 7 knots and we have easily reached 9 knots under sail in a 15 knot wind. The boat prefers to sail upright and is easily handled. In light displacement boats crew weight becomes an increasingly important factor. The three racing crew on the B7.5 contribute one half of the total righting moment. Because of its light displacement the boat feels tender initially and can be easily heeled if the crew are not prepared to hike. In a larger boat crew weight becomes a much lesser factor. In displacements over 10,000 pounds four crew have little effect on stability. An ultra light racer/cruiser would have to over 45 feet to be above that displacement. An U.L.D.B. as a cruiser would still retain the advantages of a racer/cruiser but not to as high a degree. Some extra displacement would have to be allotted to carrying of stores and cruising gear. With the invention of reliable reverse osmosis water makers it is possible to have unlimited water supply without the weight of large capacity tanks. The use of some water ballast could also be incorporated. Such a vessel could carry the usual cruising gear in good comfort but would still retain the speed that would make the most successful Admiral's Cuppers envious. With cruising speeds in the neighbourhood of 10 knots on a 45 footer passage times would be cut in half. As smaller auxiliary, spars, and winches are required the boat would be less expensive too. The smaller sailplan would make the boat easier to handle by a minimum crew. Our hypothetical 45 footer would have somewhere in the neighbourhood of 600 square feet of sail. Not bad for a 10,000 lbs boat. One advantage that has been noted in the O.S.T.A.R. when a U.L.D.B. hit a fish boat at night, was that the lack of weight allowed the boat to stop quickly and so much less damage was done. In fact the U.L.D.B. was able to make repairs and sail on unassisted. I.O.R. boats and racing centerboarders with all inside ballast have been known to pitch less. It seems that everyone is aware of the need to keep weight out of the ends of the boat but the same applies to weight down deep. Once a boat starts pitching all that ballast is swinging through the water and would gladly continue to do so. Those boats with inside ballast pitch less and go to windward better as they do not shake the wind out of their sails. Heavily ballasted boats carry their ballast much higher up in the keel and in some cases right up into the bilge. (See figure 1.) The lightly ballasted boat carries it's ballast lower allowing it to work more effectively and do the work of a much greater weight. Also the top of the keel can then be used for a water tank thereby also contributing to stability (as I did in 'Sarah'). One of the biggest safety features of a low ballast ratio is that no matter whether your boat is foam cored fiberglass, aluminium with foam sprayed in, or laminated wood, the large hull surface area with light weight will make the boat positive buoyant. Even if the boat is cut in two, each part will remain afloat. This is the one good feature of multihulls that carries over into this type of yacht. You can remain in or on your boat until you are able to make repairs, pump out the boat and continue on. In survival conditions your chances are far better out of the water and not exposed to the elements. Also you will be able to live out any rescue time in relative comfort in the boat. The large size of the vessel afloat will also be easier to spot then a small life raft at sea. When I originally began work on this project in 1974, it quickly became apparent that it would be possible to do a monohull with all the advantages of a multihull while retaining the ability to right itself at high angles of heel. A single hulled boat suitable for extensive cruising, capable of great average daily runs, of low cost as exotic materials are not required to achieve the light weight, capable of being home built, unsinkable, and with a superior motion. In fact it may even be possible to do an all out racer able to keep pace with the fastest of ocean multihulls. Now that would be an achievement! BALLAST IN THE KEEL & IT'S CENTER OF WEIGHT 12 meter boats with their 70-80% ballast ratios carry a large percentage of their ballast in the bilge. With a 25% ballast ratio the top half of the keel can be used for a water or fuel tank putting the weight lower giving the effect of greater ballast. Reference Material.
 40 Best Sailboats
 Sailors are certainly passionate about their boats, and if you doubt that bold statement, try posting an article dubbed “ 40 Best Sailboats ” and see what happens. Barely had the list gone live, when one reader responded, “Where do I begin? So many glaring omissions!” Like scores of others, he listed a number of sailboats and brands that we were too stupid to think of, but unlike some, he did sign off on a somewhat upbeat note: “If it weren’t for the presence of the Bermuda 40 in Cruising World’s list, I wouldn’t even have bothered to vote.” By vote, he means that he, like hundreds of other readers, took the time to click through to an accompanying page where we asked you to help us reshuffle our alphabetical listing of noteworthy production sailboats so that we could rank them instead by popularity. So we ask you to keep in mind that this list of the best sailboats was created by our readers. The quest to building this list all began with such a simple question, one that’s probably been posed at one time or another in any bar where sailors meet to raise a glass or two: If you had to pick, what’re the best sailboats ever built? In no time, a dozen or more from a variety of sailboat manufacturers were on the table and the debate was on. And so, having fun with it, we decided to put the same question to a handful of CW ‘s friends: writers and sailors and designers and builders whose opinions we value. Their favorites poured in and soon an inkling of a list began to take shape. To corral things a bit and avoid going all the way back to Joshua Slocum and his venerable Spray —Hell, to Noah and his infamous Ark —we decided to focus our concentration on production monohull sailboats, which literally opened up the sport to anyone who wanted to get out on the water. And since CW is on the verge or turning 40, we decided that would be a nice round number at which to draw the line and usher in our coming ruby anniversary. If you enjoy scrolling through this list, which includes all types of sailboats, then perhaps you would also be interested in browsing our list of the Best Cruising Sailboats . Check it out and, of course, feel free to add your favorite boat, too. Here at Cruising World , we like nothing better than talking about boats, and it turns out, so do you. – LEARN THE NAVIGATION RULES – Know the “Rules of the Road” that govern all boat traffic. Be courteous and never assume other boaters can see you. Safety Tip Provided by the U.S. Coast Guard  40. Moore 24 39. Pearson Vanguard 38. Dufour Arpege 30 37. Alerion Express 28 36. Mason 43/44 35. Jeanneau Sun Odyssey 43DS 34. Nor’Sea 27 33. Freedom 40 32. Beneteau Sense 50 31. Nonsuch 30 30. Swan 44 29. C&C Landfall 38 28. Gulfstar 50 27. Sabre 36 26. Pearson Triton– CHECK THE FIT – Follow these guidelines to make sure your life jacket looks good, stays comfortable and works when you need it. Safety Tip Provided by the U.S. Coast Guard  25. Islander 36 24. Gozzard 36 23. Bristol 40 22. Tartan 34 21. Morgan Out Island 41 20. Hylas 49 19. Contessa 26 18. Whitby 42 17. Columbia 50 16. Morris 36 15. Hunter 356 13. Beneteau 423 12. Westsail 32 – CHECK THE WEATHER – The weather changes all the time. Always check the forecast and prepare for the worst case. Safety Tip Provided by the U.S. Coast Guard  10. Alberg 30 9. Island Packet 38 8. Passport 40 7. Tayana 37 6. Peterson 44 5. Pacific Seacraft 37 4. Hallberg-Rassy 42 3. Catalina 30 2. Hinckley Bermuda 40 1. Valiant 40
 Pre-Owned: 1988 Hylas 47 Catalina Introduces the 6 Series Sailboat Preview: Elan GT6 Explorer For Sale: 1984 Camper & Nicholsons 58 Understanding Wind in the West Indies At Your Service Galápagos: A Paradise Worth the Paperwork
The Moody 54 Sailboat Specs & Key Performance IndicatorsThe Moody 54 sailboat, a light-displacement centre-cockpit cutter, was designed by British naval architect Bill Dixon and constructed by A. H. Moody & Son Ltd in the UK.  The Moody 54 cutter should not be confused with the Moody 54DS which, although also designed by Bill Dixon, shares few similarities with the cutter and was a much later boat, first built in 2012. Published Specification for the Moody 54 SailboatKeel & Rudder Configuration: Fin keel with spade rudder * Hull Material: GRP (Glass Reinforced Plastic) Length Overall: 16.54m (54'2") Waterline Length: 14.40m (47'3") Beam: 4.85m (15'11") Draft: 2.37m (7'9") ** Rig Type: Cutter rig Displacement: 21,500kg (47,400lb) Ballast: 8,600kg (18,960lb) Designer: Bill Dixon Builder: Moody Yachts Year First Built: 2000 Year Last Built: 2006 Number Built: Approximately 44 * Not a normal spade rudder. This one is partially balanced on a short skeg. ** A shallow draft version was also produced drawing 1.8m (5'11")  Design Ratios: The Key Performance Indicators
The Theoretical Nature and Limitations of the Design RatiosWhile the design ratios offer useful insights, they do have limitations in terms of practical application:
In conclusion, while these ratios provide a theoretical framework to assess the Moody 54's performance, stability, comfort, and bluewater capability, they must be interpreted with an understanding of their inherent limitations. Modern design innovations often transcend these traditional metrics, offering boats that perform and comport exceptionally well despite not adhering strictly to older paradigms. Read more about these all-important design ratios... What the Yachting Press had to say about the Moody 54Writing for Sailing Magazine , the celebrated yacht designer Robert H Perry tells us: "Here's a nice big cruising boat designed by Bill Dixon for Moody. The drawings show a rig with in-the-mast furling so we can assume this design is aimed at carefree cruising. The D/L of this design is 201 and that's on the light side for a boat of this type. Beam is moderate. Overhang forward is fashionably short. There are two keels offered, one with a 7-foot, 6-inch draft and another shoal keel that draws 5 feet, 11 inches. The hull shape looks reasonable although I have no lines plan. The deck plan forward looks full to my eye and that would be consistent with other Dixon designs. I like fine entries. This design has an attractive, gentle spring to its sheerline." Read more... The above text was drafted by sailboat-cruising.com using GPT-4 (OpenAI’s large-scale language-generation model) as a research assistant to develop source material; we believe it to be accurate to the best of our knowledge. Other sailboats in the Moody range include: Recent Articles Beneteau 461 Specs & Key Performance IndicatorsSep 26, 24 03:27 AM Contessa 26 Sailboat Specs & Key Performance IndicatorsSep 25, 24 02:46 PM The CSY 44 Mid-Cockpit SailboatSep 15, 24 08:18 AM Here's where to:
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 How hull shape affects comfort at sea 
Understanding how your hull shape responds to waves will keep you and your crew safe and comfortable in a blow, says Julian Wolfram  Understanding how your hull shape responds to waves will keep you and your crew safe and comfortable. Credit: Richard Langdon There are many desirable attributes sailors want in their cruising yacht.  Julian Wolfram is a physicist, naval architect, former professor of ocean engineering at Heriot-Watt in Edinburgh and a Yachtmaster Offshore who has cruised and raced for 45 years Stability is obviously a crucial factor, but there are other important factors that should be considered when judging a sailing yacht and the balance of these will depend on the type of cruising envisaged and whether there may be some club racing involved. Comfort, or seakindliness , is high on many people’s list and a boat that bounces around or slams in a choppy sea is generally shunned by all except hardened racers who will put up with any discomfort in the pursuit of speed. However, most sailors likes to sail and a boat that can’t maintain a reasonable speed in light winds and frequently requires the use of the engine is also undesirable. When the wind picks up a bit, a yacht that responds with a good turn of speed is a delight and can make the difference between arriving in daylight and tying up in the dark after a long passage.  A traditional long-keel working boat style cutter – Heard 35. Credit: Graham Snook Finally, there is course-keeping and manoeuvrability . A yacht where the helm can be left unattended for a minute or two can be a godsend to a short-handed crew , but the same crew will welcome good manoeuvrability when going into a crowded harbour or marina. A yacht regarded as being ‘well-found’ is usually a boat that responds slowly and gently to the waves and doesn’t slam when sailing or motor-sailing up wind in a bit of sea, but she may not be the fastest boat out of the blocks. Comfort depends on low accelerations, and research has shown that the travelling public feel ‘general discomfort’ when accelerations exceed 0.2g (more than 20% of the acceleration due to gravity).  A medium displacement fin and skeg sloop – Hallberg Rassy 352. Credit: Graham Snook/Yachting Monthly To put this in context, the acceleration at the top of a big, very steep wave can reach 0.5g. There are international standards on comfort, based on acceleration figures, that have to be met by operators of public transport systems and these are used in the design of manned and unmanned rail and road vehicles. Whilst we can maintain the smoothness of rails and roads you can’t do the same for the sea, so ferries have ‘operability criteria’ that limit the sea conditions in which they can operate. Of course bigger vessels are able to operate in more severe conditions than smaller ones. There are also Motion Sickness Indices based on accelerations that predict the number of passengers likely to be ill. When it comes to small yachts it’s up to the skipper and crew to decide upon the conditions in which they will stay in port.  Light displacement, modern wide hull – Pogo 10.50 This decision should depend, at least in part, on how comfortable the yacht is in a seaway. Now the comfort of yachts of the same size can be remarkably different. Take yachts of around 35ft or 10.6m long – a common yacht length. Three examples show how much the displacement can vary for this size of vessel. The Heard 35, a traditional long keel working boat type design, weighs 12.7 tonnes; the Hallberg Rassy 352 , with quite a long keel but separate skeg-hung rudder, weighs 6.7 tonnes; and the Pogo 10.50, which has a very modern wedge-shaped hull with a narrow but deep lifting keel and spade rudder, weighs 3.6 tonnes. Hull shape: RollingConsider these three yachts moored in a line when a fat motor boat goes past with a big wake. The heave (lifting) force produced by the waves will depend on the yachts’ waterplane area and these will all be roughly the same for all three. So, initially, they will all experience the same heave force. Now remember Newton’s famous law: force = mass x acceleration. This can be rewritten for boats as:- Acceleration = Force/Mass (displacement + AV M) Of course Newton’s Law is usually applied to objects in air, and when a boat moves in water it moves the water around it as well, and this must be accounted for. This is known as the added virtual mass (AVM) and it will be broadly similar for all these yachts when heaving, and has the beneficial effect of reducing the acceleration. When it comes to rolling, weight is also an advantage, given careful design and a metacentric height (GM – is the distance from the centre of gravity to the point where the vertical line through the centre of buoyancy, when heeled through a small angle, intersects the centreline. It is a measure of the initial stability or stiffness of a yacht (for small angles, GM multiplied by the angle of heel gives the righting lever) that is not unnecessarily large.  Does your boat slam or hobby-horse over waves? Knowing the difference helps you decide when you’re happy to put to sea and when you’d rather wait. Credit: Richard Langdon The sail-carrying capacity of a yacht depends on the product of its displacement and GM, so if the displacement is large the GM can be smaller. A lower GM will lead to lower angular accelerations and a more comfortable rolling motion. Let’s assume that all the yachts will heel to the same angle when setting full sail in a light breeze on a close reach. The Heard sets 92 sq. m, with its topsail up, the Hallberg Rassy 64 sq. m and the Pogo 71 sq. m which means the Heard can have a lower GM than the Hallberg Rassy and both can be lower than the Pogo. Continues below…  How keel type affects performanceJames Jermain looks at the main keel types, their typical performance and the pros and cons of each  Hallberg-Rassy 40C: The best sailing boat Hallberg-Rassy has ever built?The Swedish yard is turbo-charging its range of offshore cruisers, but have they left good old-fashioned seaworthiness behind? Theo Stocker…  Downwind secrets of ocean sailorsHow do you choose which sails to set or what course to steer, and can you stop the boat rolling?…  What makes a boat seaworthy?What characteristics make a yacht fit for purpose? Duncan Kent explores the meaning of 'seaworthy' and how hull design and… The result is that the Pogo 10 will accelerate nearly twice as quickly as the Heard 35 and about 30% more quickly than the HR352. So the Pogo 10 motion will be lively whereas the Heard 35 will respond slowly and the HR352 will be somewhere in the middle. A single wave breaking against the side of the hull will be more noticeable jerk in the Pogo 10 than in HR352 and less noticeable again in the Heard 35. Interestingly the late Ed Burnett, in discussing the design for his long keeled yacht Nomad , decided against a carbon fibre mast and in favour of a wooden one so as to keep GM smaller and the rolling motion more comfortable.  Credit: Maxine Heath The reasoning behind this decision is reflected in the diagram above, which shows the estimated roll angles and corresponding angular accelerations for our three yachts whilst on their moorings with waves on the beam. In a harbour with a 6-knot speed limit the waves generated by passing craft will be between 2m and 6m long, enough to get resonant rolling of the Pogo 10. But it needs a passing vessel to go at 9 knots to get the Heard 35 to roll. More significantly, although the maximum roll angles are reasonably similar, the acceleration is much higher for the light Pogo 10. No wonder racing crews tend to sleep ashore whenever possible. (It should be mentioned that these curves are based on simple linear theory and it is assumed the damping is the same in each case, however these approximations do not affect the broad thrust of the results.) So in general, for a given length of boat, a greater displacement will result in a more comfortable motion in the sort of waves you might encounter in an anchorage. Of course the bigger the boat the greater the comfort, and large vessels don’t move much when the fishing boats tear out at 0400! Hull shape: PitchingWhen sailing, of course, the sails will damp out the rolling motion but not the heaving and pitching. The diagram below shows our yachts going into head seas at 5 knots. Here the wave height is 30cm with a wavelength of 5m.  This goes up to 1.3m when the wavelength is 35m, which is roughly what may happen when the sea rises as the wind increase to Force 6 (25 knots). The natural period of pitching is larger for a heavy yacht and resonant pitching will occur when driving into longer and generally higher waves than for a lighter yacht. This is the one occasion when heavy displacement can be a negative in terms of comfort. The more symmetrical hulls normally associated with heavy displacement have less damping and tend to ‘hobby horse’ in these conditions. However, they can drive through a short chop comfortably with small accelerations when the light boat is having a more torrid time. Of all the yacht motions, slamming is often the one that produces the most discomfort and accelerations of over 3g have been measured by Southampton University on racing yachts going upwind. Slamming was first studied analytically by Theodore Von Karman in connection to seaplane floats in 1929. Von Karman studied, among other things, the vortex shedding behind slender cylinders, now known as a Karman Street, that gives rise to the strumming vibration of rigging and halyards in high winds. He showed how important it was to have a ‘V’ shape to the bottom of a seaplane float to reduce the slamming impact on landing. Naval architects call the angle the hull makes with the horizontal at the centreline the ‘dead rise’ .  So a flat bottom has 0° dead rise. Von Karman showed if you doubled the deadrise angle the impact force should half. Impact pressure = 1/Tangent of deodorise angle So, approximately if you increase the deadrise angle from 5o to 10° you halve the impact pressure and significantly reduce the slamming. (This formula doesn’t work when there is no deadrise, i.e. a flat bottom, and Von Karman produced a more complex analysis for this case). Unfortunately, a trend was started in the 1970s to give sailing yachts flat-bottom bows following the introduction of the International Offshore Rating rule. The rule wanted to get an estimate of displacement for each yacht without actually weighing it. That was considered too difficult at the time. So they introduced a complex series of measurements to various points around the hull beneath the waterline including some at the bow. However, yacht designers soon started to distort the hull shape at the measurement points to kid the rule that a light hull was actually heavier, which gave the yacht a better handicap than would otherwise be the case.  The diagram above shows what was typically done in the bow region to get a lighter boat with lower wetted surface area. My first personal experience of this trend came in the 1980s when I changed my Trapper 500 for a Westerly Fulmar. The Fulmar was quicker and had much better accommodation, but it was much more prone to slamming.  A Trapper 500 with V-shaped bow sections I remember motor-sailing, to catch a tide, down the Irish coast into a short chop when it seemed to slam on every other wave. The Trapper, on the other hand, rarely slammed even when my kids decided to take a shortcut through overfalls at the top of Skye while I was having an off-watch nap below – it was the pitching that woke me, not any slamming. The photos show clearly the difference in bow shape. A ‘V’ or well-rounded bow shape is the best to avoid slamming and if there is any flat area near the bow it should be small to ensure the deceleration on a slamming impact is minimised.  The Westerly Fulmar has a flattened section aft of the bow If you look at lifeboats and RIBs you will see they have deadrise angles of at least 20o, even at the stern. Going at high speed in a flat-bottom boat through a steep chop can be an ankle-shattering experience!  Draw a chalk line perpendicular to the centre line and view from ahead to get a sense of your boat’s boat sections. Credit: Julian Woolfram Drawing a chalk line around the hull mid way between the bow and the keel from the waterline on one side to the waterline on the other side and viewing from the bow will give a good impression of how seakindly, or otherwise, the bow is. If you have the body plan for the hull look at the shape of the sections near the bow. Hull shape: Wave slapNow look at the stern, if it is wide and rises at a shallow angle through the waterline to accommodate a spacious aft cabin, it will probably suffer from ‘wave slap’. Ideally the angle should be about 17o. Much steeper, especially on a wide stern, and water flow separation will increase drag; much shallower and there will be wave slap (see below).  I watched a fat little fishing boat going out at a fair lick from an inner berth in Le Crouesty marina last year and nearly half the sailing yacht sterns it passed were slapped on their undersides by its wake. Not a great way to wake up (excuse the pun) in your sumptuous aft cabin at 0530. Above and below decksThe other factor to consider in how your crew will experience the seakindliness of any boat is where they are on the boat. We all know that sleeping in the bow cabin at sea can be like a fairground ride compared to the saloon. A good sea boat will have this factored into its cockpit and accommodation arrangement, with everything that will be used at sea in the middle third of the boat’s length – heads, chart table, galley and sea berths all need to be here, close to the point of minimum motion just aft of amidships and close to the waterline (see below).  The same is true on deck. Ideally the helmsman and crew should be able to operate the boat from the forward part of the cockpit and not have to go forward of the mast, or to be perched right at the stern. While many larger boats, and some boats as small as 30ft, now have twin wheels shoved out to the aft quarters to create more cockpit space and a better view forward, this isn’t the most comfortable place to be. Tiller steering on small boats is no bad thing as it allows the helm to be much further forward, where there is less motion and more shelter.  Seaberths, galley heads and chart table in the middle third of the boat provide more comfort at sea. Credit: Graham Snook However, another person’s ideal sea boat may be very different to mine. It’s just important to understand the difference that their design makes to the conditions you are happy to set out in, understanding when it’s going to be uncomfortable, and how to handle your boat when the wind does get up.
 Offshore sailboat choices Editor’s note: There are many types of hull design, rig configuration and material choices for offshore sailboats. We talked to four voyaging couples and asked them about the pros and cons of the choice they made when they decided on a voyaging boat. Rich and Cat Ian-Frese Tayana 37 Anna Rich and Cat Ian-Frese left Seattle after an 11-year refit of their Tayana 37 cutter, Anna . They started out heading in the general direction of South America, where they eventually took a right turn and crossed the South Pacific. They have refit, cruised and lived aboard Anna since 2000. Rich has a background in research engineering and spent many years working on research grants in emerging laser technologies. He has worked as a project director on R&D projects for the U.S. Department of Energy, the National Science Foundation and NASA. Cat spent over 20 years teaching elementary school, including special education. Ocean Navigator: Why did you decide to voyage in a heavy-displacement boat? Rich and Cat Ian-Frese: My wife and I decided to voyage in a full-keel (with cutaway forefront) heavy-displacement monohull, a Tayana 37 cutter rig, because it has a comfortable and easy motion in the ocean. It feels solid and stable and safe in big waves, even in big confused waves — although the comfort factor is noticeably reduced in big confused waves, as it would be on any vessel in rough seas where the waves are big, short-spaced and coming from multiple directions. This will cause bashing into a headwind and heavy, lumpy rolling dead downwind. In our opinion, a heavier displacement vessel will absorb getting knocked around better than a light-displacement monohull. ON: What are the advantages and disadvantages of this type of offshore boat? R&CI-F: The advantages of a heavy-displacement monohull, like the Tayana 37 cutter, are a very stable and comfortable ride in normal ocean conditions. The Tayana 37 has modest initial stability for a moderately heavy displacement boat, and it will comfortably heel over initially to dig in and pick up speed and add to its waterline length. And then its secondary stability kicks in, which is effective in keeping you sailing at a comfortable heeling angle. We’ve never felt the heeling angle to be unsafe, even in big rolling seas.
We don’t feel that there is any significant disadvantage to a heavy-displacement boat that is used for ocean voyaging, unless speed is your priority. We’ve never been in a situation where not being able to outrun bad weather resulted in a bad outcome. We think that it would be advantageous at times to attain a knot of speed for every knot of wind, like some fast monohulls and catamarans we know of, but we’re happy to slip along at 4 to 7 knots. It seems less stressful on the boat and rig, and less stressful on the crew as well, especially when conditions deteriorate. Besides, we like being on the ocean and don’t place a lot of emphasis on getting from point A to point B in record-setting time. But that’s just us; we can certainly see how hull speeds of 10 to 20 knots can be appealing when you actually have a chance to get ahead of a forecast bad weather system or have simply just had enough rolling on a 3,000-mile passage. Many heavy-displacement vessels are full keeled. And while a full-keeled monohull like the Tayana 37 has advantages on the ocean — like righting itself quickly if rolled in heavy seas, and having an easy motion in normal seas, an excellent balance of primary and secondary stability, and a modest turn of speed — there is perhaps a disadvantage in close-quarters work. In marinas where getting into a Travelift dock or a fuel dock involves backing up in a straight line in windy conditions or in a strong current, maneuverability can be a challenge. We could never back up our Tayana 37 down a narrow fairway and expect to end up exactly where we want to go. It’s not in the nature of the Tayana 37. Bow thrusters are, of course, an option, but we didn’t have thrusters on our boat. Many other boats with long keels, other than the Tayana 37, are simply bad when the transmission is thrown into reverse. Occasionally, we are lucky and the wind and current help us along. But generally the less distance we need to go in reverse, the better. Normal docking and turning in narrow fairways is fine. Just don’t expect consistently perfect results in reverse gear in a heavier breeze or fast-running current with some full-keel boats. We had a Pearson 30 a long time ago. It had a light displacement and a spade rudder. It could turn on a dime and back down a long narrow fairway in almost any conditions. But there are tradeoffs with any boat. We would never think of taking that vessel on a long ocean voyage with its unprotected rudder. When most of your time is spent on longer passages in unpredictable conditions, a good stable boat that you have complete confidence in when the weather goes south is most important. ON: For voyagers considering a heavy-displacement sailboat, what advice would you give? R&CI-F: We wouldn’t hesitate to sail a heavy-displacement boat. Personally, we’d feel more secure in conditions that were other than ideal. A heavy-displacement monohull doesn’t guarantee comfort in heavy weather, but it will buffer the ride and offer a degree of stability and security that you may feel is lacking in a light-displacement boat. If you want speed and comfort running downwind in the South Pacific, then a catamaran might be right for you. There are light-displacement catamarans and also moderately heavy displacement oceangoing catamarans about 48 to 50 feet in length that could take you just about anywhere that a shorter, stout, heavy-displacement monohull could. We choose the Tayana 37 cutter for its ruggedness in the ocean. It’s comfortable for a short-handed crew to operate, it’s economical at 37 feet and it has never let us down when in heavier ocean conditions over the past 20 years. It’s utilitarian. You might call it the Jeep of sailboats.
Phil and Lynda Christieson Kauri ketch Windora Phil and Lynda Christieson from New Zealand have owned and cruised extensively on Windora , a 43-foot Kauri ketch, for the last 26 years. They circumnavigated with their two sons in the ‘90s and are now completing a six-year cruise in the higher latitudes. Ocean Navigator: Why did you decide to voyage in a wooden-hulled boat? Phil and Lynda Christieson: When we went looking for a cruising yacht, we were extremely lucky to find Windora , a proven offshore vessel, within our budget. Coming from New Zealand, where wooden boats are built from far superior materials, there was never any question that a wooden boat was inferior, and we learned very quickly that we had an exceptional boat. Being of wood construction, the interior is a piece of artwork, leaving you in no doubt that you are on a real boat, not a floating caravan. ON: What are the advantages and disadvantages of this type of offshore boat? P&LC: Windora is a composite wooden boat, strip-planked with a heavy layer of epoxy glass fiber. This creates a high-strength, totally dry hull. It provides the most comfortable environment to live in, both in tropical and high-latitude climates. Repairs and maintenance can be done in the most remote places with easily available materials. There are large areas of the planet where you are treated differently because you sail a wooden boat. You are not just another white plastic boat; you stand out in the crowd. A traditionally planked wooden boat cannot be left on the hardstand for extended periods.
ON: For voyagers considering a wooden-hulled sailboat, what advice would you give? P&LC: First choice would be wood-composite construction, which lets you use two-part urethane paint systems, allows for minimum maintenance, and gives you the advantage of being able to store the boat ashore in the most extreme climates. You need to ensure the surveyor has a good understanding of wooden boats, as they are the most complex in construction of all the materials. A poorly built wooden boat can be hugely expensive to put right. Never touch any wooden vessel with iron fastenings in it. Dave and Sherry McCampbell St. Francis 44 catamaran Soggy Paws Dave and Sherry McCampbell left Florida in May 2007 and headed west across the Pacific via the Panama Canal. They spent eight years getting across in their 1980 CSY 44 monohull. By 2015, they were ready for a faster boat and switched to a 2005 St. Francis 44 MK II catamaran. After four years exploring much of eastern Southeast Asia and a number of significant modifications, they now have the perfect cruising home. Ocean Navigator: Why did you decide to voyage in a multihull? Dave and Sherry McCampbell: We are full-time international cruisers. There were many reasons we switched from our 1980 CSY 44 monohull to our 2005 St. Francis 44 catamaran. But the bottom line is that it was better suited to our increasing age and desire for more safety, more comfort and less maintenance. Below are the most important reasons to us that we switched. These mirror some of the most important advantages and disadvantages of a catamaran versus a monohull. ON: What are the advantages and disadvantages of this type of offshore boat? D&SM: Here are what we see as the main advantages.
Level sailing: Cats sail relatively flat, so there is far less fatigue on a passage. Because of this, we can finally read and do computer work most of the time underway. That was rarely possible on the CSY monohull while rolling along at a 10- to 15-degree heel. This is really important for full-time cruisers and not well understood by the monohull cruising community. See the Navy study from a few years ago on page 24 of my presentation link below. Layout: There is typically about 40 percent more room on a modern cat than on a monohull of similar length. A cat layout is much more cruising-friendly, with daily living, navigation and watch-standing areas up, and bunks, storage, heads and mechanical spaces down. The main saloon and cockpit are on the same level, so there’s no need for a ladder transit between them. It is also easier to access multiple storage lockers along the sides of two hulls instead of one, or searching for things under bunks and in the bilges. Two engines: Modern cats generally have better speed and fuel economy while motoring. Motoring at 5 knots with one small engine properly loads up the engine and uses roughly half the diesel we used to use with the CSY. That means we can carry roughly half the fuel we used to carry for a 1,200-nm range. Two engines also means a full spare parts inventory is always on board, and there is no drama if one should develop a problem needing repair at sea. Maintenance: The newer boat and more room mean generally easier maintenance for electrical and mechanical equipment. No teak on deck means no varnish work ever! A more modern rig makes rigging work and sail handling easier. Unsinkability: Many modern cats won’t sink regardless of damage, due to a thick foam-cored hull, waterproof crash compartments and lack of lead keel. Our cat has a 1.25-inch foam-cored hull and deck, and is advertised as non-sinking unless really overloaded. That is a really comforting feeling while underway in deep water hundreds of miles from land. We think staying aboard is a better option than having to abandon ship into a life raft. Stability: Cats have better stability at anchor, in a seaway or riding to a sea anchor. Little rolling means better sleep at night. It also means most things left on counters and tables will stay put underway in reasonable conditions. Availability of strong, wide bridle attachment points at the ends of the forward crossbeam reduce yawing and therefore ground tackle loads. Speed: Most comparisons I have read indicate about a 20 percent speed increase on long passages. We rarely want to go more than about 8 knots, and we start reefing at about 7 knots. This compares to reefing at 6 knots on the CSY. We are comfortable at 7 to 8 knots on the cat. In the open sea, we consider anything more than about 9 knots uncomfortable due to increased boat motion and rig loads. Sail handling: Wide, flat decks with little roll mean safer sail handling and reefing at sea. The jib is relatively small compared to the main, so it is easier to handle than on most monohulls. Also, no pole is required for downwind sails or a spinnaker.
Dinghy storage: Cats offer much safer and more convenient dinghy storage if lifted on high davits aft between the hulls. Typically, modern cats allow the dinghy (with motor on) to be taken out of the water easily and launched quickly. There is no need to remove the outboard and store the dinghy on the foredeck before making a passage. Draft: The cat’s shallow draft gives many more anchoring options. This is especially important if looking for that mangrove-lined, unoccupied tropical cyclone hole. The ability to do a free haulout for repairs or a bottom paint touch-up on a beach is a huge advantage. It is easy to do on many beaches with just a few feet of tide. Most of the monohull vs. catamaran comparisons, as well as catamaran features, are well covered in our PowerPoint presentation, “ Evaluating Modern Catamarans ,” available on our website. ON: For voyagers considering a multihull, what advice would you give? D&SM: There is no perfect catamaran with all the features you may want, so be prepared to compromise somewhat. However, knowing what works and what does not for the cruising you plan to do is important. Be sure to research this carefully before starting to look for a cat. With the number of catamarans being produced on the rise, there are many designs to choose from. However, not all are created equal. Although most cruisers spend 90 percent of the time in port, due consideration should also be given to features that enhance safety and comfort at sea. Most catamarans are optimized for tropics cruising and are probably not the best choices for high-latitude voyaging. There is plenty here to consider before purchasing a cruising catamaran. Much more is on the Internet. Many modern cats are built for the lucrative charter trade and may have features that don’t work well for full-time bluewater cruising. Some of these can be corrected or improved, some cannot. Be suspicious of exaggerated dealer claims, ask for proof of anything that doesn’t seem right, and ask specific questions. Consider making a list of what to look for before going shopping. As with almost all cat owners I’ve talked to now that we have made the switch to the “enlightened side,” we would never go back.
David Content & Roslyn Stewart Aluminum sloop Barefoot David Content and Roslyn Stewart have been sailing their boat, Barefoot , in the Pacific for eight years. Roslyn has previously sailed in Papua New Guinea and northern Europe. David has sailed extensively in the North and South Pacific. Ocean Navigator: Why did you decide to voyage in an aluminum boat? David Content & Roslyn Stewart: My present voyaging sailboat is Barefoot , a 43-foot aluminum boat designed by Angelo Lavranos and built by Dearden Marine. I chose an aluminum boat after having already sailed more than 50,000 ocean miles in an excellent 36-foot, IOR-design fiberglass boat. Most influential in the decision was wanting a solid, strong boat that was still reasonably lightweight and would withstand the stresses and wetness experienced for weeks at a time on offshore passages. I learned from cruisers sailing metal boats that they did not develop leaky chain plates, slack stays and shrouds, water intrusion in the rudder, loose keel bolts or squeaky interior liners at the bulkheads, even after thousands of ocean miles. For me, an aluminum boat was a better choice than steel because steel boats require a watertight paint coating on all metal surfaces. I wanted to avoid the paint maintenance, and I desired the lighter weight of an aluminum fabrication. ON: What are the advantages and disadvantages of this type of offshore boat? DC&RS: An aluminum boat is difficult to paint and doesn’t need it above the waterline. On Barefoot , the unpainted topsides are gray and protected by a naturally developing oxide coating. Some sailors perceive this as an advantage, while others prefer to paint the topsides for cosmetic purposes. An obvious advantage of aluminum is that the robust cleats, chocks, handrails, stanchion sockets, chain plates, anchor rollers and genoa track bases are all permanently welded directly on the deck. In addition to being extremely strong, no potentially leaky deck penetrations exist. Inside the boat, aluminum frames and stringers serve as solid attachment bases for the interior handrails, autopilot ram, steering cable sheaves, and the generator and watermaker mounts.
Non-obvious advantages of an insulated aluminum boat are numerous. One example is that the insulated hull pulls the cabin and bilge temperature toward the water temperature rather than the air temperature. This means in the tropics we’re able to stow fruit and veggies in the cool bilge, and that no deck canopy is needed to keep the cabin cool, even in the tropical sun. Conversely, when sailing at high latitudes, the water temperature is warmer than the air and that keeps the boat naturally warmer. Two disadvantages of aluminum boats are the cost of construction and the watchfulness required to avoid corrosion problems. Well-built aluminum boats are more expensive than production fiberglass sailboats. Aluminum fabrication costs are based on the material expense of proper aluminum alloys for hull plating, frames and stringers, and on labor costs for skilled aluminum welders. The construction process is more labor intensive than fiberglass boats. Potential corrosion sources in aluminum boats are well understood by builders these days. Following best practices in electrical wiring and equipment isolation from the hull eliminates most corrosion risks. An aluminum boat owner can prevent corrosion by learning a few unique requirements. For example, an isolation transformer must be wired in the boat if connected to shore power; a charcoal filter must be used when filling an aluminum water tank from a city chlorinated water supply; never moor the aluminum boat next to a steel boat; never use chlorine cleaners for anything (use vinegar); and always have installed and regularly check an LED light indicating a fault from a connection between the hull and the positive or negative side of the battery. ON: What is your advice for voyagers considering an aluminum vessel? DC&RS: They should follow the same process as with the considered purchase of any boat: Talk to sailors who have a similar boat, inspect as many aluminum boats as possible, and consider having a custom boat built by selecting a good naval architect and finding a small, experienced aluminum boatyard for the build.  By Ocean Navigator14 Best Monohull Sailboats  Monohulls are among the most popular boats in the world accounting for over 75% of the total number of boats. This means that choosing the best monohull sailboats for your sailing adventures can be overwhelming. Fortunately, we're here to help you by highlighting the best monohull sailboats. Whether you're an accomplished sailor or just starting in the world of sailing, a monohull boat is an ideal option for anyone who wants a true sailing experience. Unlike other types of sailboats, the level of adrenaline that a monohull brings to your sailing adventure is almost unmatched. It doesn't matter whether the conditions are rough , wild, flat, or calm, a monohull is the perfect boat type for anyone looking for the thrills of the sail. Unfortunately, you might not fully enjoy the thrills of sailing on a monohull sailboat if you do not choose the best monohull sailboat for you. While a monohull cannot compete with multihull sailboats in terms of cabin size, anchoring closer to the shore, and comfort, it should hold its own if you are planning to spend more time at the sea and in unpredictable conditions. A monohull sailboat will definitely be an ideal option if you're planning to go to more challenging places. This is exactly why you have to make the right choice when looking for the best monohull sailboat. Over the years, we've sailed many monohull sailboats and that's precisely why we feel confident that we can help you choose the best monohull sailboats. We've gone through various designs and launches, tested them, and sifted through many monohull brands to select the best monohull sailboats that we strongly believe should be on your bucket list. So without further ado, let's walk you through them. Table of contents Best Monohull Sailboats{{boat-info="/boats/amel-55"}} For several decades, Amel 55 has not only been the epitome of easy downwind handling but has developed a cult-like following among sailors. It was designed as the successor to the legendary Super Maramu and brings to the fore incredible features that every serious sailor will value. From a sturdily built hull, solid guardrails to a skeg-hung rudder, watertight bulkheads, and lush bulwarks, Amel 55 is built with anything you could ever want in a perfect monohull sailboat. And even with a list of standard features, this monohull sailboat is truly designed for those who want to live comfortably on a sailboat for long periods. It comes with superb sea berths with lee cloths, a dishwasher, crockery, an electric furling main and genoa, and several practical items that will make sailing very comfortable. We have to admit that the design might look old going by modern standards, especially with the advent of easier sail handling systems. For example, the ketch rig design is no longer ideal and is out of fashion. But even with this downside, the Amel 55 remains a phenomenon; a legendary monohull sailboat that ticks all the right boxes in the sailing world. 2. Bavaria Cruise 46{{boat-info="/boats/bavaria-46-cruiser"}} Probably the most popular monohull sailboat in recent years, the Bavaria Cruise 46 is a formidable monohull sailboat that was voted "European Yacht of the Year" in 2015. Well, this shouldn't be surprising as you'll probably never find another monohull sailboat in its class that offers more comfort, more space, more luxury, and easier handling. You can transform the boat's 3 cabins into 4 cabins by transforming the huge forward cabin into two smaller cabins in a few simple steps. In the bow, you'll find a large and luxurious master cabin that can be easily divided using an innovative Flexi-bulkhead. Its sporty design on the exterior, lightweight composite steering wheels, and a flexible selection of wood tones makes it look so good while offering the best dimensions for both short and long trips. In essence, the Bavaria Cruise 46 is an elegant monohull sailboat that redefines modern sailboats with its clever and innovative design. 3. Hallberg-Rassy 48 Mk II{{boat-info="/boats/hallberg-rassy-48-mk-ii"}} Following in the footsteps of the original Hallberg-Rassy 48 Mk that was launched a decade ago, the Mk II was launched in 2014 as an updated version thanks to its modern profile, incredible hull portlights, and larger and frameless windows. This Swedish monohull sailboat is solidly built, gorgeously finished, and is famous around the world and among sailors for its kind and smooth behavior at sea. Its center cockpit is a true definition of what comfort should entail at sea. This is a monohull sailboat that will provide you with steady sailing both upwind and downwind. It can effortlessly cover 200 miles a day and doesn't require you to be a pro sailor to be able to handle it. If anything, it offers smooth sailing and can be perfectly handled by a casual sailing couple . In terms of additional features, this monohull comes with a large chart table, lots of stowage and space, a secure linear galley, as well as extra machinery and gear that would be of great help when out on the water. This is a well-thought-out monohull sailboat and is perhaps the best Hallberg-Rassy ever built. This boat guarantees reliability, top-notch quality, and superb resale value. 4. Catalina 545{{boat-info="/boats/catalina-545"}} As one of the largest monohull sailboats in the game, the Catalina 545 stands out in the way it's engineered and designed to make it a truly excellent monohull sailboat. If you're an ardent Catalina fan, you'll notice that the 545 has some of the most eyebrow-raising features in bluewater cruising. For example, the fiberglass collar is designed all-round the top of the hull and shaped like a construction beam. This is to give the hull a more enhanced rigidity while providing a sturdy base for the deck. It's also designed with solid stanchions and cleats, as well as strong sheer rails. This superb monohull sailboat is constructed with a set of scuppers that play a crucial role in draining near the waterline so that you can perfectly eliminate any development of streaks or strains on the top side of the boat. As far as the bow is concerned, the sprit brings to the table an essential but unique anchor roller, a self-tacking jib, and a light displacement that makes the boat quick even in light or moderate wind. In essence, this monohull sailboat is designed with simple but reliable systems that are easily accessible. Better still, it remains one of the biggest monohull sailboats around. 5. Discovery 55{{boat-info="/boats/discovery-55"}} Having been launched two decades ago in 2000, the Discovery 55 has unquestionably stood the test of time and remains one of the most preferred monohull sailboats for families and couples around the world. This is a well-balanced and elegantly designed sailboat that brings to the sailing world immense practicality, comfortable seating, a deep and secure cockpit, dedicated stowage, and a self- tacking jib among many other things. If you've been on a sailboat and bruised or stubbed your toes, you simply appreciate hos the superb monohull sailboat is designed to keep you safe and secure at all times. From the grab rails and handholds to deep sinks in the galley, the Discovery 55 is designed with plenty of nifty details and the inclusion of many practical ideas. This sailboat will probably never disappoint you. It is well-mannered, comfortable to live on for days if not months, and a true definition of modern and luxurious. 6. Contest 50CS{{boat-info="/boats/contest-50cs"}} If you want a serious monohull boat that can help you extend your sailing ground with ease and perhaps without even realizing it, the Contest 50CS is the way to go. For close to two decades, this Dutch-made monohull sailboat has been a consistent performer even with its dry weight of 17.5 tons. This monohull is designed with impeccable modern underwater sections and a completely balanced rudder. Although the in-mast furling may affect the boat's performance, this boat can still perform incredibly well without it. The fact that this boat is designed with a mainsheet traveler and electric winches that can be easily accessed from the helm makes it an ideal boat for a small crew or if you're planning to sail shorthanded. The genoa is easy to tack and two people can easily gybe downwind under spinnaker. In addition to having exceptional touches on the interior, you might be surprised to learn that the joinery finish of this boat is arguably among the best in the boating industry. This is a monohull sailboat that's easy to handle, well-built, and has weathered the test of time to still mix it nicely with the big boys of recent years. Well, the Contest 50CS might not be among the cheapest monohull sailboats around but its demand is still soaring even today. 7. Bénéteau Oceanis 45{{boat-info="/boats/beneteau-oceanis-45"}} Named yacht of the year in 2012, the Bénéteau Oceanis 45 remains one of the most popular monohull sailboats in the world and for a good reason. This is a sailboat that redefines the important themes that made the Oceanis 50 so popular in a much better way. One of the most noticeable features of this boat is that the mainsheet is designed in such a way that it doesn't obstruct the cockpit as you tack or jibe. This just a start; the cockpit is nicely designed and will serve you just right during your sailing endeavors. This monohull sailboat comes with three or four cabins, two bathrooms, and has a larger cockpit than other boats in its class. This is a boat that keeps up with the Bénéteau tradition of being ahead of the game in terms of innovation, attention to detail, and offering top-notch performance. Whether you're looking to live aboard or sail to the remotest of places, this gorgeous monohull sailboat has everything you need in place. 8. Jeanneau Sun Odyssey 36i{{boat-info="/boats/jeanneau-sun-odyssey-36i"}} Another French monohull sailboat that makes it to this list, the Odyssey 36i is a great monohull sailboat that is acknowledged for having some excellent assets in terms of sailing as it is faster and more agile than most sailboats. This is, without a doubt, an elegant monohull sailboat that brings to the sailing world an overall melodious package in terms of its modern design, power, and capability when sailing. Even though its hull is of modest size, this monohull sailboat offers great value as it is easy to sail, easy to moor, and dock. Its magnificent electronics, folding prop, and electric anchor winch seem to make everything so easy that you do not even need a crew to sail this boat. The hull is lively and offers good acceleration. Imagine a monohull that can clock around 6.4 knots when sailing upwind. To be honest, the interior of this boat is still very traditional but the exterior looks quite modern. The exterior is designed like an avant-garde sailboat and looks appealing from just about every angle. In terms of performance, this boat is designed with a deeper keel, spinnaker gear, taller rig, and a much better standing and running rigging. On the interior, the most noticeable feature is the removable dining table that can be easily removed to accommodate extra bodies. Apart from that, there is nothing complex about the cockpit and deck layout. The double-roller bow fitting is nice and it comes with an optional electric windlass. In essence, this monohull sailboat is designed with lots of features. It is good-looking and reasonably priced. 9. Gunfleet 43{{boat-info="/boats/gunfleet-marine-gunfleet-43"}} For many sailors who have the dream of spending most of their time sailing to exotic places, the prospects of downsizing and living most of your essentials at home can be daunting. In other words, it's almost impossible to pack all your life in a 40 feet vessel if you've lived your entire life in a 2,000 feet house. While you can't bring things like your hot bathtub to the ocean, the Gunfleet gives you the chance of bringing most of your essential onboard thanks to its immense spaciousness. This British-built monohull sailboat is modern, sleek, but kind of feels like a classic sailboat. It comes with an efficient hull that's laid up by hand to enhance attention to detail. The reverse transom brings to the fore a three-step ladder leading to the deck and a small swim platform. It's also designed with a low coach roof and a windshield that seems to taper towards the aft of the cockpit. Its impeccable low profile gives it a contemporary look but the center-cockpit design is the most attractive part of its design. The aft deck section is expansive and comes with excellent twin zones for sunbathing. They're divided by a skylight and a hatch that lead to the master stateroom that's located below. Its two cabins and two heads are essential if you're planning for long passages. The interior is posh and offers ample natural light. As far as performance and acceleration are concerned, this monohull sailboat holds well. It accelerates nicely even when out of tacks since the helm is responsive no matter the point of sail. This is an outstanding monohull sailboat that has a solid feel and will most certainly boost your confidence if you're planning to go for long passages even in snobbish conditions. 10. Island Packet 35{{boat-info="/boats/island-packet-35"}} Designed to offer top-notch performance, stability, and comfort, the Island Packet 35 is widely known for its spaciousness, modern interior, U-shaped galley, and a vast cockpit that certainly compares to most modern 40 feet sailboats while still holding to the classic lines. This incredible monohull sailboat is designed with a short spoon, generous spring to the sheer, and a chopped off transom. It is perfectly designed bowsprit elongates the sheerline, which essentially makes the boat appear longer, lower, and much better than it is. As far as the keel is concerned, this is a full keel that's not heavy but very moderate. The interior of this boat will probably make you think that you're looking at a 40-footer sailboat. It's so spacious that you can use it for your liveaboard sailing escapades. It also offers notable improvements in performance and certainly surpasses some of the company's earlier models. In ideal conditions, very few boats will match the Island Packet 35 in terms of performance. This is a very stable and comfortable monohull sailboat that doesn't hold back as far as performance is concerned. 11. Bowman 40{{boat-info="/boats/chuck-paine-bowman-40"}} Thanks to its medium-to-heavy displacement structure, the Bowman 40 is designed to sail across open seas with ease. A modern classic, this monohull sailboat looks pretty much traditional thanks to its overhanging bow, deep-bilged, and narrow shoulders. This makes it very powerful on the waters and offers a lot easier motion during long passages. Better still, this sailboat is perfectly stable and enjoyable since you won't be thrown about even in strong waves. It's designed with handholds within reach both above and below the deck, as well as no sharp edges to ensure that you don't injure yourself. This is enabled by the balanced hull and carefully integrated sails, as well as ample ballast that's neither heavy nor lightweight. In short, this is a solidly built monohull sailboat that will serve you diligently even when you are confronted with stormy conditions. Honestly speaking, the Bowman 40 isn't a racing cruiser but neither is it a slouch. It has the ability to sail through the heaviest of oceans and might arrive at your destination just at the same time as other lightweight sailboats. This is, without a doubt, a sailboat that's designed to take you offshore in all weather and sea conditions. 12. Bavaria Cruiser 51{{boat-info="/boats/bavaria-51-cruiser"}} Even though it is one of the largest monohull sailboats, you'll probably never notice this once you start sailing. Well, this is because it handles unbelievably so well and can easily and comfortably accommodate up to ten crew members thanks to its three cabins. To offer optimum luxury, this boat can be customized to have five cabins, which is clear evidence that it can meet various needs. This boat isn't just about being spacious. Instead, it's designed with all functionalities to enable you to enjoy your sailing adventures. Whether you take a look at its exterior, interior, deck, or cockpit, you'll realize that every part of this gorgeous monohull sailboat oozes class. While the most striking of this vessel's interior is its enormous space, it's also designed elegantly and beautiful to ensure that you enjoy your sailing adventures. In terms of its hull, you're getting a very agile boat that you can easily control even when the winds are extremely strong. In essence, this is a monohull sailboat that's well and generously proportioned in all aspects. It's modern, sleek, and will turn head whether at the dock or deep at sea. 13. Wauquiez Centurion 57{{boat-info="/boats/wauquiez-centurion-57"}} Thanks to its exciting Mediterranean-style design and functionality, the Centurion 57 is a serious monohull sailboat that feels robust, solid, and truly marks the reincarnation of the legendary Centurion generation of luxury monohull sailboats. Designed as a racing sailboat, the Centurion 57 is thoroughbred, powerful, and impeccably maneuverable but that doesn't mean that you have to use it as a racing cruiser. Instead, it's comfortable, luxurious, and elegant and brings to the fore everything that French boat makers are known for: class, beauty, and reliability. Its hull is unquestionably one of the most powerful and versatile. It's designed to withstand the harshest of sailing conditions . It has a very spacious and large cockpit that's designed to afford you maximum versatility while out there. This means that you'll get lots of free space to efficiently maneuver the boat in the tightest situations and also to make things a lot easier if you're sailing shorthanded. From the electric winches to the helm position, you can easily access the transoms. This is a monohull sailboat that guarantees calm, luxury, and comfort without compromising on performance and speed. It oozes modernity, solidity, and immense attention to details. 14. Rustler 42{{boat-info="/boats/rustler-yachts-rustler-42"}} If you've been looking for a monohull sailboat that combines serious performance attributes to other crucial blue water cruising elements, look no further than the Rustler 42. This is a gorgeous, fast, and reliable monohull sailboat that remains the benchmark of all monohull sailboats of its size. It not only offers directional stability but can also carry immense loads and is solid enough even for long passages. This is a classing looking monohull sailboat that perfectly combines traditional style with modernity and innovativeness. It is not only elegant but also very stable and should be an ideal choice if you're looking for the best liveaboard monohulls. Its spacious cabin is big enough to offer standing headroom and, of course, plenty of storage within the lockers. The hull is hand-laid using glass fiber reinforced polyester to ensure that it's solid, reliable, and durable. In ConclusionThere you have it; the above-described vessels are the best monohull sailboats today. They are designed to enhance your sailing experience and ensure that you always enjoy your time out there on the water. Whichever boat you choose, it's essential to ensure that it's in good condition, well-maintained, and in perfect shape for your adventures. Until next time, stay safe and happy sailing! Related Articles  Daniel Wade I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing. by this author Best Sailboats Most Recent What Does "Sailing By The Lee" Mean?October 3, 2023  The Best Sailing Schools And Programs: Reviews & RatingsSeptember 26, 2023 Important Legal Info Lifeofsailing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies. 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COMMENTS
An Ultra Light Displacement Boat (or ULDB) is a term used to refer to a modern form of sailboat watercraft with limited displacement relative to the hull size (waterline length). Principally manufactured from the mid 1970s through mid 1980s, these boats generally sit higher in the water allowing them to move faster in nearly all water types ...
A mong the dockside pundits, the discussion of light vs. heavy displacement usually revolves around the ability of a cruising sailboat to carry the necessary provisions and gear for extended cruising. I would like to consider the question from another angle: appearance and cost. L ight displacement boats have some real advantages. Up to a certain point, lighter displacement saves money, both ...
The load-carrying capacity of smaller light-displacement boats can be a concern. Clearly if you load, say, 1,500lb of stores and equipment on a 25ft boat with a Displacement/Length Ratio of 200 it will have a greater effect than if you loaded the same amount onto a forty footer of the same Displacement/Length Ratio. The 25 footer's Displacement ...
A light displacement boat might pound in a seaway, and a heavy one is likely to provide a softer ride. The second ratio of interest is the sail area to displacement ratio. To calculate, take SA / (D)^0.67 , where SA is the sail area in square feet and D is displacement in cubic feet.
Standard displacement, also known as "Washington displacement", is a specific term defined by the Washington Naval Treaty of 1922. [11] ". It is the displacement of the ship complete, fully manned, engined, and equipped ready for sea, including all armament and ammunition, equipment, outfit, provisions and fresh water for crew, miscellaneous ...
The Olson 30 is one of a breed of sailboats born in Santa Cruz, California called the ULDB, an acronym for ultra light displacement boat. ULDBs basically are big dinghies-long on the waterline, short on the interior amenities, narrow in the beam, and very light in both displacement and pricetag. ULDBs attract a different kind of sailor-the type ...
0. The Olson 30 is of a breed of sailboats born in Santa Cruz, California called the ULDB, an acronym for ultra light displacement boat. ULDBs are big dinghies—long on the waterline, short on the interior, narrow on the beam, and very light on both the displacement and the price tag. ULDBs attract a different kind of sailor—the type for ...
The lower a boat's Displacement/Length (LWL) ratio, the less power it takes to drive the boat to its nominal hull speed. less than 100 = Ultralight; 100-200 = Light; ... Some report light displacement which is the weight of the hull and permanent equipment but with empty tanks. Light displacement does not include stores, removable equipment ...
A displacement hull is a boat hull design that uses buoyancy to support its weight. It lies partially submerged and displaces water when moving, hence its name. The amount of water it displaces is equal to its weight. It's very stable in rough waters. That's why this design is widely used on cruisers and sailboats.
The shark is a light displacement cruising and racing sailboat. It has a 7/8 fractional sloop rig, a small cabin and a self-bailing cockpit. The iron fin keel, combined with a transom hung spade rudder, and a flat run aft allows the hull to ride up on its bow wave and plane under the right conditions, giving the Shark more speed than a ...
An ultra-light racing yacht may have a D/L Ratio of 80 or so, a light cruiser/racer would be around 140, a moderate displacement cruiser be around 230, a heavy displacement boat will be around 320 while a Colin Archer type super- heavy displacement cruiser may boast a D/L ratio of 400+.
A moderate displacement boat, a powerful rig, and a sea-kindly hull will produce a boat that drives upwind, through chop, and carries a spinnaker large enough to preserve a lead. PHRF 30 to 70 ...
The formula takes the long ton weight of the yacht (its displacement in pounds divided by 2,240) and divides it by a hundredth of the waterline length (measured in feet), cubed. Ultra-light displacement yachts have a D/L ratio of less than 100. Light displacement is 100-200. Most coastal cruising yachts have a moderate displacement of 200-300 ...
A D/L ratio is calculated by dividing a boat's displacement in long tons (2,240 pounds) by one one-hundredth of the waterline length (in feet) cubed. ... especially when in displacement mode. If there is less water to push aside, wavemaking drag is reduced. Some ultralight-displacement boats, or ULDBs, are light enough to plane just like a ...
Heavy Displacement: 9 long tons and 32 foot waterline = 274.7. If we add 2 people to the yacht, the following will happen. Light Displacement: 3 long tons becomes 5 long tons, a 40% increase in the weight of the boat. Medium Displacement: 6 long tons becomes 8 long tons, a 25% increase in the weight of a boat.
In light displacement boats crew weight becomes an increasingly important factor. The three racing crew on the B7.5 contribute one half of the total righting moment. Because of its light displacement the boat feels tender initially and can be easily heeled if the crew are not prepared to hike. In a larger boat crew weight becomes a much lesser ...
Designed by the legendary California sailor and surfer George Olson, the Moore 24 was one of the first ultra-light displacement sailboats, or ULDBs, and launched a whole movement of fast, fun speedsters based loosely out of Santa Cruz. A downwind flyer, some 160 boats were built in a 16-year production run that began in 1972.
The Moody 54 sailboat, a light-displacement centre-cockpit cutter, was designed by British naval architect Bill Dixon and constructed by A. H. Moody & Son Ltd in the UK. The Moody 54 cutter should not be confused with the Moody 54DS which, although also designed by Bill Dixon, shares few similarities with the cutter and was a much later boat ...
Light displacement, modern wide hull - Pogo 10.50. This decision should depend, at least in part, on how comfortable the yacht is in a seaway. Now the comfort of yachts of the same size can be remarkably different. Take yachts of around 35ft or 10.6m long - a common yacht length. Three examples show how much the displacement can vary for ...
The lower a boat's Displacement/Length (LWL) ratio, the less power it takes to drive the boat to its nominal hull speed. less than 100 = Ultralight; 100-200 = Light; ... Some report light displacement which is the weight of the hull and permanent equipment but with empty tanks. Light displacement does not include stores, removable equipment ...
In our opinion, a heavier displacement vessel will absorb getting knocked around better than a light-displacement monohull. ON: What are the advantages and disadvantages of this type of offshore boat? R&CI-F: The advantages of a heavy-displacement monohull, like the Tayana 37 cutter, are a very stable and comfortable ride in normal ocean ...
The Olson 30 is a sailboat designed by George Olson of Santa Cruz, CA around 1978. Olson was a surfer and surfboard shaper who decided to design a 30' ultra light displacement boat while on a delivery from Honolulu to Santa Cruz on Merlin, a 68' Bill Lee designed and built [1] ultralight sailboat which had competed in the biennial Transpac race in 1977. . During this delivery, Olson came up ...
As far as the bow is concerned, the sprit brings to the table an essential but unique anchor roller, a self-tacking jib, and a light displacement that makes the boat quick even in light or moderate wind. In essence, this monohull sailboat is designed with simple but reliable systems that are easily accessible.