How Does a Jet Ski Work?

A Jet Ski Uses a Gas Motor

Personal watercraft, sometimes known by their brand name "Jet Ski," rely on a gas-powered engine to propel themselves and a few riders through the water. The fuel feed to the engine is controlled by a thumb-button or trigger located on the right handlebar of the watercraft; because the jet ski relies on the resistance of the water to slow down, a corresponding brake pedal is not necessary. Like any other gasoline-powered engine, jet skis require fuel and oil to properly function.

An Impeller Provides Thrust

When the rider starts the jet ski and pulls the throttle trigger, the engine accelerates a water pump known as an impeller. This pump ingests water from the immediate front of the watercraft and forces it out the rear of the jet ski at a high velocity, providing thrust and forward movement. The more fuel supplied to the engine, the more powerfully the water is expelled by the impeller, producing acceleration and faster speeds.

The Impeller Also Provides Control

On most jet skis, the impeller is linked to the handlebars so that turning the handles also turns the impeller's nozzle, providing a water-based steering mechanism. When the handlebars are turned left, for example, the impeller is turned to push water out the right rear of the watercraft; the reaction of the jet ski is to begin a left turn.

Accessories Provide Safety and Enhancements

A plethora of aftermarket jet ski accessories is available, providing endless combinations of safety and functional enhancements. One of the more popular accessories routes a small fraction of the impeller's output vertically into the air. This "rooster tail" provides a distinctive marker indicating the presence of a personal watercraft to other nearby boaters. Additional accessories might include handlebar upgrades, waterproof radios and under-seat storage solutions.