An outboard motor is a propulsion system for boats, consisting of a self–contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method of propelling small watercraft. Yamaha Mercury Suzuki Honda are best producers of these outboard engines. As well as providing propulsion, outboards provide steering control, as they are designed to pivot over their mountings and thus control the direction of thrust.