Come summertime 2015, the first of Heesen Yachts’ 180-foot (55-meter) fast displacement, steel-hulled motoryachts will be delivered. The aggressively styled megayacht’s name is being withheld for now, but she bears the hull number YN 17255.
Last year, Heesen unveiled three proposals bearing a fast displacement hull form designed by Van Oossanen Naval Architects, with this megayacht being among them. (On a related note, this megayacht marks the fourth Van Oossanen fast displacement design being built by Heesen, and the two companies’ 10th collaboration overall.) The designs were presented to potential clients and the media alike, in response to the increasing desire among megayacht owners to lower fuel consumption without sacrificing performance. The fast displacement hull form is more fuel efficient than traditional round-bilge, hard-chine hull forms. It incorporates design changes to the spray rails, bulbous bow, and more that have a large effect on hydrodynamic resistance over the whole speed range, rather than just top speed.
In terms of this project’s performance, twin 1,850-hp MTU 12V 4000 M53 diesels should permit a half-load top speed of 16.5 knots and a range of 4,500 nautical miles at 13 knots. Perry van Oossanen of the eponymous design firm says that only about 800 hp should be needed to make the megayacht achieve 15 knots at the half-load 600-ton displacement.
The hull form form YN 17255 is also a bit narrower than traditional yacht hulls, bearing a 31’5” (9.6-meter), beam. That’s about two feet narrower than others of this LOA. But, the amenities for YN 17255 don’t seem as if they’ll suffer. The owners get a private alfresco area and a balcony off their main-deck suite. They and their 10 guests also have a 1,184-square-foot (110-square-meter) sundeck at their disposal. As the rendering above also shows, there’s a nice-size beach club at the transom, further containing a gym. Tenders go in a garage forward, concealed behind gull-wing doors.