Boat rudders may be either outboard or inboard. Engines are installed either inboard or outboard. Both inboard and outboard engines are used. Runabouts can be powered by inboard engines, outboards, jet drives, or inboard-outboard (I/O) drives. Each set consisted of a high-pressure outboard turbine which exhausted into a low-pressure inboard turbine. Two semi-balanced rudders were mounted behind the two inboard screws. Two semi-balanced rudders were placed behind the two inboard screws. The inboard propeller windmilled to a stop. This point is located between the fuselage and the left inboard engine. Small hooks were fitted just forward of the inboard flaps. Sufficient braking capacity allowed for thrust reversers to be installed on only the inboard engines. Wishbones are triangular and have two widely spaced inboard bearings. The boat was factory fitted with a range of inboard engines. Control is achieved by moving the engine with a lever attached to the inboard side. One innovation in "Essex" was a portside deck-edge elevator in addition to two inboard elevators.