Pump-jet

A pump-jet or water jet is a marine system that creates a jet of water for propulsion. The mechanical arrangement may be a propeller with nozzle, or a centrifugal pump and nozzle.

Pump jets have some advantages over bare propellers for certain applications, usually related to requirements for high-speed. 

 Other websites 
 Personal Watercraft Industry Association
 American Watercraft Association 
 U.S. Coast Guard Boating Safety

Category:Engineering