Removable jet propulsion unit for watercraft

A water jet propelled boat comprised of a hull defining a tunnel at the rear under side thereof, said tunnel being defined between a pair of side walls and a top wall, a jet propulsion unit mounted within said tunnel for propelling said boat, the transom of said hull having a portion extending between said side and top walls for substantially closing the rear of said tunnel and defining a relatively small opening at the lower portion thereof through which the jet propulsion unit may be removed so as to provide a relatively rigid transom of the jet propelled boat, said jet propulsion unit being mounted within said tunnel for movement between a normal operative position for propelling the boat and a raised position for raising the water inlet opening of the jet propulsion unit to an out of the water position, the top wall of said hull defining said tunnel being sufficiently high so as to permit said jet propulsion unit to be moved between said positions while substantially within said tunnel, the upper end of said relatively small opening lying substantially below the rear end of said top wall.