Abstract: A high-speed hydrofoil craft has a hull supported by a foil. When the foil is submerged, the upper surface of the foil may be ventilated by atmospheric air to form an air-filled cavity, in which case the foil performs similarly to a planing foil.

Abstract: A hydrofoil craft has a hull supported above a water surface by a foil connected to the hull by means of a support arm. In accordance with one form of the invention, the support arm enables the foil to move up and down with respect to the hull in concert with upgusts and downgusts of water surrounding the foil so as to maintain the hull at an approximately constant elevation. In accordance with another form of the invention, the support arm is supported by the hull for pivoting about a longitudinal axis extending in substantially the fore and aft direction of the hull. When rolling forces act on the foil, the support arm can pivot about the axis from a vertical position in response to the rolling forces while enabling the hull to remain substantially level.

Abstract: A hydrofoil craft which possesses at least one hull, at least one support arm which extends from said hull into the water and which is connected to the hull, at least one foil attached to each support arm, and preferably at least one shock strut per support arm which pivotally connects said hull to the support arm, so that said shock struts allow the support arm and the foil to move in concert with the upgusts and downgusts of water velocity located near the foil so as to enable said hydrofoil craft to maintain approximately constant lift. The principles involved are also applicable to aircraft of the "wing in ground effect" type which is designed to fly close to the water's surface so as to take advantage of the favorable aerodynamic effects of the water's proximity.