How Does a Marine Jet Pump Work?

Marine jet pumps can propel boats and personal watercraft at high speeds.

Marine jet pumps are used for propulsion in jet boats and personal watercraft. They work by creating a fast jet of water and directing it out the stern of the vessel.

Enclosed Propeller

Water is drawn from outside the vessel into the pump jet housing. A rapidly spinning propeller accelerates the stream of water back out through a nozzle to propel the boat. According to NASA, a cooperative work between Jacuzzi and the University of Georgia developed marine jet pumps to power Navy vessels and pleasure boats.

Centrifugal Pump

Some marine jet propulsion systems use centrifugal pumps to create a high pressure water stream to move the vessel. A series of back-swept impeller blades turn at high velocity to create the jet.

The Intake

The jet pump needs water to provide the thrust to move the boat. The intake duct is covered by a mesh screen that keeps trash and weeds out of the pump. The gland seal around the intake prevents from air leaking into the pump, which can cause reduced thrust.

References

• NASA: Marine Jet Pump
• Intelli Jet: The Basics of Jet Propulsion

Resources

• Read this Article in Spanish
• American Turbine: Understanding Your Jet Boat