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Why it's time for a radical rethink of sailing yacht design
From stubby to bows to stern terraces, there's a reason designers might be encouraging a radical rethink for your next sailing yacht. Risa Merl reveals all...
Yacht owners are accustomed to sleek bows, whether it’s a sharp plumb or the more modern reverse – narrow shapes that cut through the waves and look good doing it. Yet the ideal bow for a sailing yacht, according to designers and shipyards, might surprise you. In fact, you might even find it downright ugly.
“The most efficient sailboat looks a lot like a shoebox,” says yacht designer Philippe Briand. “That’s because for the given length, this rectangular shape offers maximum waterline length, maximum stability and better seakeeping.” Let that sink in for a minute.
A principle of the “scow” shape he’s referring to is that it maximises hull righting moment, which is the best measure of a boat’s overall stability. Briand says it also has the added bonus of achieving maximum interior volume for the length. “The more you go to the shoebox shape, the better the accommodation,” he says.
Although a square-shaped scow bow might look quite different from what we are used to, it is not that new. Sailboats in the 19th century used this shape, originally inspired by scow barges. Scows were seen in everything from racing dinghies to Great Lakes schooners.
But if this is one of the most efficient – and voluminous – bow shapes, then why is it not the norm? “The reason we haven’t seen many scows over the last 150 years or so is that hull shapes were limited by rules that would make the sailboats perform the same for racing purposes,” says Briand. As racing rules evolved, granting more freedom in regards to stern volumes, we began seeing sailboats that were beamier – and lighter as well – closer to the proportions of boats built in the 1960s and 70s, which Briand dubs “the golden age of sailing”. For many years, bows were all about five to seven degrees in angle, which moved gradually towards the vertical, especially in cruising yachts, says designer Olivier Racoupeau of Berret Racoupeau. This style spread around the world, and the most familiar look became a sharper bow entry with a beamy stern.
In the past decade there have been more whispers about the ugly duckling scow design. The shape has proven a successful contender – and winner – in Mini Transat races and more recently has shown up in the new America’s Cup foilers. Other than a few standard America’s Cup rules, there are no significant limits on the structure of the boats in the 36th Cup. The differences in the new boats are best seen in the hulls as design teams seek minimal drag and good stability. NYYC American Magic’s Defiant and Ineos Team UK’s Britannia are early adopters. The latter has clean scow lines with a boxy bow and a wide hull.
As is always the case in the sailing world, racing technology soon trickles down to the rest of the fleet. Take the new Nautor’s Swan ClubSwan 36, designed by Juan Kouyoumdjian. The Finnish builder likens this innovative yacht with a fast hull to a modern supercar. The ClubSwan 36 has a noticeably unusual bow shape, and while it might not look like a standard scow, Swan attests that the styling is inspired by scow designs. “The bow is an interpretation of a scow, like the squared bows of the boats sailed in the [American] Great Lakes,” says Enrico Chieffi, Nautor’s Swan's CEO. “The whole concept of this boat is a relatively wide hull, so when the boat starts heeling it sails on a narrow body on the waterline length on the leeward side.”
The design team is looking to reach some performance goals in this yacht, such as a low surface area, a grade of symmetry when the boat is heeling and excellent buoyancy when sailing downwind. It’s the first time Nautor’s Swan has explored the scow shape, which Chieffi says is developing quickly in yacht design. “We discussed it for some time, but the difference is in the aesthetics,” he adds. “It’s different from what we and our clients are used to.”
Of course, there is always compromise. Scows are far from perfect, Briand admits: “A shoebox is good when there’s wind, but it has too much resistance in light wind.”
According to Chieffi, the shipyard is motivated by performance, but that comes down to what is the best performing design for the mission of the yacht. “If you have a cruising yacht that is also meant to motor some of the time, the disadvantage of a bow like this is that when the boat is upright and you motor against the waves, you will [present] a big surface to the waves, which would not suit cruising, so we would not utilise this on a traditional cruising yacht.” In cruising boats, you also want a longer deck, while in racing boats you shorten the deck to improve windage.
But will aesthetics become a roadblock to seeing the scow go mainstream? “Most clients are not ready to accept it,” says Briand. “A [scow shape] would look too extreme.”
That doesn’t mean other bow shapes aren’t good performers. Plumb and reverse bows both maximise the waterline length, and the greater waterline length the greater speed, as Erik Wassen of Dykstra Naval Architects explains. “The plumb bow as featured on Hetairos and Kamaxitha offers a longer waterline for the same LOA,” he says. “Inherently, the hull-speed potential increases.” Wassen points out that if Hetairos had a spoon bow with the same overall length, it would be eight metres shorter on the waterline. “The hull speed reduction with this [spoon bow] is a hefty 1.2 knots – that’s considerable.” But there’s more to it than that. Increased waterline and enhanced water plane area also improve stability. And it’s good for volume too.
The last seven Baltic Yachts’ bows are all plumb, but Royal Huisman has released the concept for an 88-metre DynaRig, designed by ThirtyC and DynaRig creators Dykstra, dubbed Project Lotus, which has a distinctive reverse bow. “It is more a styling feature and will effectively not contribute to a performance increase for a yacht of this size,” says Wassen. “Although you could claim that there is less volume in the bow, hence less weight can be installed or collected there, which helps to keep the yacht lighter.”
It’s no surprise that bow shapes have an impact on the interior, with a longer waterline length allowing for more volume. “Depending on size of boat, many have owner’s cabins up front, so the new fuller bows provide much better volumes for owners,” says Chieffi. At the other extreme, a traditional raked bow makes an easier job of anchoring. The use of a bowsprit can solve the problem that yachts with plumb and reverse bows can find when mooring.
Racoupeau has created sailing catamaran designs with both plumb and reverse bows. He credits vertical plumb bows with increasing a yacht’s flotation length, which in turn increases speed, but, “on a reversed bow design, we have the same advantage, plus the improvement of the sea behaviour,” says Racoupeau. “Personally, from an aesthetic point of view, I really like the dynamism of the reversed bows.”
Wassen prefers the plumb bow. “For speed potential, the plumb has the advantage: long waterline; least added resistance in waves; reasonably dry on deck,” he says. “The clipper/schooner bow might be drier in a seaway and offers more deck space, but the reversed bow is wetter and provides less real estate.”
Designers and yards are in agreement that there isn’t a major difference in terms of building costs, although the scow might cost a bit more because it requires a larger sail plan in order to exploit its full speed potential.
Beyond the bow, there are other innovations in sailing yacht design that we’ve seen in recent years in terms of water access. Baltic’s Pink Gin VI had a hull door opening up in the master, while Vertigo had a side door from the gym.
“I love hull doors and balconies,” says Racoupeau. “But these remain a costly and complicated device. It is probably the reason for why we don’t see more of [them].”
Chieffi agrees: “We are generally against side entrances or openings in sailing yachts. They are common on power boats, but structural engineering constraints are substantially more complex on sailboats. All these solutions are difficult, heavy and inefficient, unfortunately.”
Sailing yacht sterns have evolved as well. Today’s yacht owner, notes Racoupeau, is more interested in easy access to the water for enjoying water sports, which is why an opening stern and beach club set is becoming more prevalent in sailing yachts – driving boats to grow in size and scope. Nautor’s Swan is experimenting with a new stern solution on the Swan 120. “It turns completely from a closed stern to a terrace on the sea, and we are building the first version of this now,” Chieffi says.
At the end of the day, the styling of a yacht’s bow, stern and everything in between still has a lot to do with looks. The differences between plumb and reverse bows is small, says Racoupeau; it’s a question of aesthetics. “[The preference] is linked to the styling of the project, and from this point of view, it’s really more about fashion,” he says.
If fashion rules, we may not see an onslaught of scows anytime in the near future, but it is clear that designers and builders are pushing the innovation envelope of bow and hull shapes more than ever – much of it inspired by those who pave the way in racing yacht design. And that’s OK, really. Appearance is an indisputable consideration during yacht building, along with performance attributes, as Wassen attests: “An owner enjoying the styling of their yacht is just as important a factor in their enjoyment of yachting.”