Abstract: An apparatus for self-righting a rigid inflatable boat in which the boat includes an elongated hull having a determinable center of gravity and beam width. The boat hull has an elongated rigid bottom and inflatable sidewalls which have top, bottom and inner edges. An inflatable arch member having first and second leg portions extending upwardly and inboard from opposite sidewalls of the hull converges at a central point spaced outwardly a first predetermined vertical distance above the top edges. The first predetermined distance is at least equal to the sum of one-half of the beam of the hull, plus a distance equal to the vertical distance, if any, at which the center of gravity may be located above the sidewalls' bottom edges. Each leg portion has an axial centerline which extends upwardly and inwardly substantially between its respective sidewall and the central point.

Abstract: A self-righting inflatable life raft including a raft body having inflatable sidewalls and an inflatable member extending from the raft body having a buoyant portion sufficient to provide lifting force to move the raft's center of gravity beyond its point of rotation on the surface of water such that the raft will topple by gravity to an upright position. The inflatable member may include a plurality of inflatable tube portions which extend from an upper edge of the raft sidewalls to a first predetermined position upwardly and outboard from the upper edge and which then extend inboard to centrally converge with one another at a second predetermined position above the raft body.