These propulsion systems have the advantage of having no propeller to cause potential danger to people in the water and marine life. They are usually inboard engines that take in water that flows through a pump powered by an impeller. The water is then discharged at high pressure through a nozzle that propels the boat forward. The nozzle swivels to provide steering to the boat. Most personal watercraft use jet drives.
Note: When power is not being applied, a jet driven vessel loses its steering because it is the stream of water that steers the boat. Keep hands, feet and hair away from the pump intake and do not operate in shallow water.