This design of a 43.5 meter Semi-Displacement motor yacht for Dutch Yacht Builders was based on a concept by Cor D. Rover Design.
We carried out all of the naval architecture work in 2006/2007 and the construction commenced in September 2007 and the yacht was launched in the summer of 2009.
The design brief called for an easily driven hull with special regard to the required propulsion power and fuel economy. The maximum speed requirement was not the main issue but the maximum cruising speed was. Computational Fluid Dynamics calculations were used to develop the hull form. The development of this hull form played a role in the subsequent development, at Van Oossanen & Associates, of the Fast Displacement Hull Form, for which a patent application has been applied. Twin MTU 16V2000M93 engines were selected (1790 kW at 2450 rpm), giving the yacht a top speed of 20.7 knots and a fast cruising speed in excess of 16 knots. The fuel economy is exceptional with figures of 7.8 litre per nautical mile at 12 knots, and 14 litre per nautical mile at 16 knots, in combination with normal generator operation.
The hull form is essentially of the round-bilge type, with spray rails in the fore body. The application of trim wedges fitted to the inside of the propeller tunnels provide sufficient lift at the stern to keep the running trim near horizontal throughout the entire speed range. A bulbous bow is fitted to reduce wave-making resistance.
Special attention was given to the design of the propeller shafts and appendages and the propellers themselves. This has helped in obtaining very low noise levels (less than 55 dBA at 75% MCR).