Propulsion System For Boats

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 motorized method of propelling small watercraft. 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. The skeg also acts as a rudder when the engine is not running.