The latest thing in superyachts is “fast displacement”. Obviously, for anyone who knows anything about boats, the term is something of an oxymoron – a full-bellied displacement yacht being something that sits sedately in the water, while lean, fast yachts zoom past, planing noisily over the surface. The twain don’t meet: displacement designs are limited to low speeds by the laws of physics, while their speedy sisters tend to wallow ungraciously unless they’re cantering along at a reasonable clip.
In fact, fast displacement is less an oxymoron than a holy grail. Because for the true superyacht experience – comfort, quality and a prodigious wine cellar – only a displacement yacht will do. Luxury, if it is more than skin deep, carries a significant weight penalty, and weight is the enemy of the planing hull. Yet not all superyacht owners are happy to cruise at a sedate 12 knots, whether they’re on board themselves, or planning to join the yacht in Porto Cervo at the weekend, only for the captain to confess that the last charter left them at the wrong end of the Med and the boat can’t meet them until Tuesday.
There is nothing new about this. It wasn’t so long ago that all boats were displacement models. But owners still wanted to go fast, so even before those laws of physics were properly understood, designers knew that the speed of a beamy, full-bellied hull is limited by the wave system it generates when under way. Fast boats had to be long and thin. “Think of a plank on edge, travelling through the water like a blade,” says Monaco naval architect and superyacht designer Espen Øino. “It doesn’t make waves.” And consider a rowing eight: although most of the weight is pure muscle, the real reason those frighteningly fit young men can reach speeds of 12 knots or more is because their boat is very long and very, very thin.
There is an obvious problem: a 60m superyacht built to the same proportions as a rowing eight would be about 2m wide. There would be nowhere for the grand piano or wine cellar. But fortunately you don’t need to go to quite such extremes to cheat the wave system. Perhaps the quintessential narrow-beam superyacht was Carinthia VI, later known as The One, a sometime fixture of the Monaco waterfront and yacht of such transcendent gorgeousness that her loss in January to a fire in Turkey was met with genuine sadness in the superyacht world. Back in 1971 she was a breakthrough project both for her designer, Jon Bannenberg, and her German naval architects and builders, Lürssen. With twin 5,600hp engines, her slender hull could slice through the seas like a luxury warship at speeds of up to 28 knots.
Elegant, fast and fuel-efficient, perhaps she ought to have been more influential. But these admirable attributes were not pursued by an industry that found itself increasingly and happily beset by new owners with no background in yachting and whose standards of luxury had been acquired from grand hotels. Superyachts grew not just longer, but taller and wider as well, so that today’s typical superyacht of The One’s length – 70m or so – boasts about twice her internal volume, has a top speed of around 16 knots, and looks like a cruise ship.
There will always be owners for whom quality trumps quantity, however, and speed is one quality that seems to have a special allure. Lately Øino has designed a succession of yachts for one owner that take advantage of the narrow-beam concept. The aluminium Silver series is sleek, swift and slender, and the latest of them, the 77m Silver Fast, debuted at the Monaco Yacht Show last autumn – having made the 21-day trip from the Australian shipyard where she was built with just one fuel stop. “The owner knew what he wanted – to be able to move quickly and efficiently. He had owned displacement yachts before,” Øino explains. “We looked at commercial designs – rig crewboats in the Gulf of Mexico, fast ferries – that were efficient and reliable and built using the same narrow-beam idea.” But not too narrow: although at 10m she is only slightly wider than The One, according to Øino Silver Fast’s beam is still adequate to provide the volume necessary for superyacht standards of space and luxury. “The cabins are actually quite big,” he says.
Øino’s innovative layout for the yacht gives the owner the entire upper deck to himself, with a private saloon, his and her ensuites, an open-air “retreat” aft, and a spectacular, elevated, forward-facing cabin with 270-degree views. There are also three double VIP suites on the main deck and four ensuite guest cabins down below. None of these compares with the scale and opulence enjoyed upstairs by the chap with the chequebook, though, which is probably fair enough. The key to the Silver’s success, according to Øino, is that “it’s not extreme. We wanted to avoid at all costs the expense and complexity of triple engine installations, and especially gas turbines. We chose to go the simple route and create as few problems for ourselves as possible.” So Silver Fast has the same propulsion geometry as the average family motor cruiser, albeit on a grand scale: two 3,648hp diesel engines linked to conventional gearboxes, shafts and propellers.
This is a yacht with a top speed of 27 knots and a seriously long-range cruising capability – she can reel off 450 nautical miles a day for 10 days straight. But although these numbers are impressive compared with beamier and heavier conventional superyachts, Silver Fast is not especially groundbreaking in the esoteric world of naval architecture, as Øino is the first to acknowledge. That accolade goes to the new 70m Heesen superyacht Galactica Super Nova. Although rather beautifully styled by Øino’s Monaco studio, her radical underwater shape was designed by the Dutch naval architecture firm Van Oossanen, which has devoted years of research and tank tests to improving the performance and efficiency of superyacht hulls, both for long-range cruising and short, exhilarating blasts at maximum speed.
“Hard-chine hulls designed for going fast are very inefficient at cruising speeds,” explains joint managing director Niels Moerke. “We wanted to fill the gap between full planing and displacement hulls.” So Galactica Super Nova has generous width and interior spaces. There is a palatial owner’s suite on the main deck, plus four guest cabins down below and an extra VIP suite upstairs. She has a 12-seat dining table, a huge and professionally equipped galley and a 6m waterjet-powered pool. A central crystal lift shaft is encircled by a steel and leather-trimmed spiral staircase. Her toys and tenders are launched through side doors in the hull, and her foredeck converts into an open-air cinema. For sheer style, opulence and capacity she is the equal of any conventional superyacht. But she is also capable of long-range cruising and, when required, the massive power provided by triple engines can show a clean pair of heels to just about anything else her size on the water.
In setting themselves the task of merging all these qualities into one yacht, Van Oossanen’s naval architects refined and developed the design of the traditional bulbous bow – used on low-speed vessels for decades – to an unprecedented degree. The resulting complex, sculpted shape increases efficiency by 15 per cent at high speeds, while offering no drag penalty in the cruise.
At the other end of their patented fast displacement hull, the carefully calculated curvature of the stern takes the pressure generated as the hull slips through the water and directs it forward, so the hull is effectively helping to push itself along. An interceptor plate across the transom juts into the water and prevents the stern from squatting down as speed increases. Keeping the yacht level allows the hull to function at peak proficiency, Moerke explains.
Much of Van Oossanen’s model trials were carried out at Southampton University’s Wolfson Unit, which concluded that this advanced new shape was simply the most efficient they had encountered in almost 50 years of tank testing. What that means in practice is that Galactica Super Nova, a yacht designed to achieve 30 knots at full throttle, also has a cruising range of 4,000 nautical miles using just two engines. To combine both these capabilities in one spectacularly well-appointed superyacht is something quite new.
Of these two remarkable superyachts, from opposite ends of the earth, one was built to tried and trusted principles, while the other was based on radical new thinking. Both advance the cause of efficient superyachting and both show that speed and efficiency need not be mutually exclusive. Whether either of them represents that holy grail, however, only time will tell.