Abstract: A hull with a convexly down-stepped plane located in the aft section and a "V" shaped hull structure in the forward section. The "V" shaped section and the planar section are connected by a smooth, convexly shaped transition section that is convex in reference to the exterior of the hull and extends below the "V" section. The transition section can be provided with spray root deflectors. The planing surface extends substantially the full width of the lower portion of the hull and can have portions of its after portion upwardly displaced.