The 110-metre HEMY (High Efficiency Motor Yacht) concept from Laurent Giles aims to deliver superior performance and fuel efficiency compared to a typical 75-metre yacht. “The concept was to start with a typical 70-75-metre yacht and lengthen the hull to offer increased interior volume and remain within a 3,000 GT limit. Not only does the HEMY offer increased accommodation volume, but with its more efficient length/beam ratio and lighter displacement/length, it offers significant improvements in performance and seakeeping,” says David Lewis, managing director of Laurent Giles. “If the HEMY concept had the same power as a typical 75 metre, it would achieve speed improvements of two to three knots, and can achieve the same cruising or top speed for about 65% of the power, with corresponding savings in fuel consumption.”

Laurent Giles says that a typical modern superyacht packs in as much accommodation within a given length, increasing the beam and superstructure, and producing heavy and hydrodynamically inefficient vessels operating at high speed-length ratios and requiring high power to achieve this. “Naval architects have long known that, for a given speed, the longer, leaner and lighter the vessel the better in terms of performance and efficiency, but the superyacht market largely ignores this,” Laurent Giles says. The low hydrodynamic drag of the hull form of the 110-metre HEMY, which has a 12.5-metre beam, is enhanced by a low, simple superstructures to reduce windage drag and keep the centre of gravity low. The yacht will also sport a hybrid diesel-electric propulsion system.