A molded boat hull is provided having a channel forming member extending between a motor mounting transom and an aft riser that forms a step in the bottom portion of the boat hull. The channel forming member has at least one open side and at least an opening in another side to provide a fluid flow communication channel from the atmosphere to the underside of the boat in the step area. The channel forming member is formed as an integral part of the boat hull during forming of the boat hull by molding.