The Wow!10too hydrofoil is fixed in position, but can be slid out for transportation and light air sailing. It curves upward and outward from the boat’s bottom. The attack angle is +6º when the boat is sailed flat fore to aft. To adjust the attack angle the skipper moves his/her body forward or aftward. To increase the foil’s depth of immersion the skipper moves to leeward. When sailed flat, the forward edge of the hydrofoil where the hydrofoil enters the hull is just below water level. The gunwales, forward and aft of the hydrofoil, consist of buoyant volumes which provide anti-heeling assistance by increasing the lever arm of the hiking force. The beam at the waterline is narrow to reduce form drag. The bottom is almost flat to enhance planing. Sail standard area is 119 square feet (11 sq meters). Options for sail areas of 53, 75 and 96 square feet will also be available The hull weight is approximately 45 lbs. The hydrofoil decreases the apparent weight of the boat, reducing skin friction and form drags. The boat is about 10 feet long. The leeward part of hydrofoil increases the hiking lever arm when heeling.
An alternative rig is also possible which uses the mast from an 11 rig with a raised boom and the sail from a 9 rig. In this situation the boat can be sailed standing up, combining the features of a windsurfer and a dinghy.
The image above shows rig 9. The hydrofoil causes the amount of lifting force to increase as boat speed increases.
The foil acts as a lifting hydrofoil when immersed and a planing board at high boat speeds. Thus the foil is referred to as a planing hydrofoil.