Abstract: A tetrahedrally shaped pivotable sailing frame of four spars and a sail with balanced hydrofoils is disclosed. A hydrofoil sailboat is created by pivotally attaching the frame to a hull along a longitudinal axis of the hull. Tacking is accomplished by rotation of the frame about that axis. Although the sailing frame can be adapted to a variety of types of hulls, including windsurfers, catamarans, and multiple-hulled craft, a preferred embodiment of a hull is disclosed which in combination with the sailing frame affords the proper lift and forward vectors and obviates the need for a keel, live or dead ballast, or sail adjustments. The lift affords very high speeds and minimal wetted surface. The tetrahedral structure of the sailing frame is stiff, giving a level, stabilized ride and permitting an optimal surface area of sail. The hull design provides swift, easy tacking and reduces the possibility of backwinding.