Abstract: A planing type self-righting boat having rigid pontoons forming its perimeter structure independent of interior inflation and which, during the vessel's normal operation, protect conventional or modified interior inflatable pontoons which elements together are used in whole or in part as essential mechanical components in the automatic self-righting of the vessel upon capsizing. The self-righting of the vessel after capsizing is effected by the creation of a negative buoyancy and subsequent sinking of that portion of the vessel whereby this submerging action combined with the weight and configuration of the vessel cause it to rotate underwater to a position beyond perpendicular to its capsized position while the vessel is supported by the buoyancy retained in the remainder of its pontoon structure.