Central hydrofoil development for fast boats

Hull Vane BV has been working on the patented innovation for several years and it aims to support a major portion of the vessel’s weight on the foil rather than on its hull at the waterline. The underlying principle wasn’t to achieve full hydrofoiling, but partial hydrofoiling in order to improve performance and seakeeping, much like the company’s transom mounted Hull Vane.

Early in the development process, the company built and successfully tested a prototype yacht. To achieve the goals, the company had to work out how to stabilise a vessel using only one main foil. They were successful, and the patent is now pending.

The Foil Assist is a small, passive, wing-shaped device made of solid stainless steel attached amidships beneath a vessel’s hull. It is designed to withstand cornering forces and to damp pitching motions in choppy conditions.

Partially supporting the vessel’s weight on the submerged wing, rather than at the waterline, helps reduce the effect waves have on performance. And because the Foil Assist only partially lifts its hull out of the water, the vessel is said to handle much more predictably like a normal planing vessel, than a fully hydrofoiling vessel. It is also said to be less sensitive to different trim and weight loadings due to differing crew and cargo, than a full hydrofoil

Initial research with a Wajer 32 S superyacht tender has shown that the Foil Assist reduces fuel consumption by 10 to 20% while reaching top speeds of 45 to 48 knots with a 3 to 6% power reduction.

Hull Vane (Van Oossanen Naval Architects) claims Foil Assist is the next step in increasing speed and efficiency while reducing power requirements for high-speed yachts, fast patrol boats, naval interceptors, sea rescue boats and pilot boats. This makes the Foil Assist an invaluable, future-proof enhancement for all fast-planing hulls.

This new product will be built, sold and marketed by Hull Vane BV, who have years of experience with other submerged foil appendages, including the custom Hull Vane, semi-custom Hull Vane and Dynamic Hull Vane.

By Jake Frith