Pump-jet

Plates, similar to rudders, can be attached to the nozzle in order to redirect the water flow port and starboard.

In a way, this is similar to the principles of air thrust vectoring, a technique which has long been used in launch vehicles (rockets and missiles) then later in military jet-powered aircraft.

Mixed flow designs produce lower volumes of water at high velocity making them suited for small to moderate craft sizes and higher speeds.

[2] Pump jets have some advantages over bare propellers for certain applications, usually related to requirements for high-speed or shallow-draft operations.

[5] On December 3, 1787, inventor James Rumsey demonstrated a water-jet propelled boat using a steam-powered pump to drive a stream of water from the stern.

[7][8][9] On December 21, 1833, Irish engineer John Howard Kyan received a UK patent for propelling ships by a jet of water ejected from the stern.

[10] In April 1932, Italian engineer Secondo Campini demonstrated a pump-jet propelled boat in Venice, Italy.

Examples of ships using pumpjets are the Car Nicobar-class patrol vessels, the Hamina-class missile boats, Valour-class frigates, the Stena high-speed sea service ferries, the Royal Navy Swiftsure, Trafalgar and Astute-class submarines, as well as the United States Seawolf and Virginia-classes, and the Russian Borei-class submarines.