Abstract: The inflated geometry of an inflatable skirt wall constituting at least a part of the cushion sealing means on an air cushion vehicle (A.C.V.) is changed to effect a shift in the center of pressure of the vehicle supporting air cushion for assisting in directional control or to reduce the overall width dimension of the A.C.V. when the skirt wall projects outwardly of vehicle rigid body structure while maintaining a skirt structure sufficient to contain an air cushion for slow speed maneuvering of the A.C.V. Means for changing the inflated skirt wall geometry comprise duct means and co-operating valve means for controlling supply of pressurized air to one or more compartments of the skirt structure, and further duct means and co-operating valve means for venting air from said one or more compartments.

Abstract: Bow and side deck structures forming a part of the rigid body structure of an air cushion vehicle include a tubular circular section gunwale member and a tubular circular section chine member supported outwardly from a buoyancy tank structure which forms the base of the rigid body structure by frame members to which they are attached by welding. The bow and side deck structures are completed by hull plating attached to the gunwale, chine and frame members. The buoyancy tank structure may include unstiffened extruded deep I-section beams.