Design and Build of a Hydrofoil Boat

Abstract

To investigate techniques of personal watercraft design and manufacturing, while exploring the functional use of hydrofoils, a small hydrofoil watercraft was designed and built.

The hull of the boat is a skiff measuring 14 feet and 5 inches in length and weighing 142 pounds. This hull was designed and built as a platform to support the development of the hydrofoil attachments. The watercraft is powered using a 15-horsepower outboard motor, an Evinrude Super Fastwin 1953, restored for the purpose of this project. Two surface-piercing dihedral hydrofoils were affixed to the hull to provide lift sufficient to raise the main hull out of the water. The dihedral surface piercing foils also provide the height control and roll stability necessary for stable flight. The hydrofoils are removable and thus allow the watercraft to be operated as a conventional personal watercraft when foiling is undesired. Estimates based on the hydrofoil boat design and manufactured components predict a takeoff velocity of 5 knots, with foils at a 6° angle of attack, a flying weight of 566 pounds, and a drag at takeoff of 283 pounds.