Marine jet propulsion unit

摘要

The marine jet propulsion unit comprises a water intake casing (1) with an impeller casing (2) connected to the intake casing. An impeller (3) is provided within the impeller casing and a water outlet casing (4) is connected to the impeller casing. A rotatable member (5) is associated with the water outlet casing for controlling the direction of discharge of water from the unit. A normally-closed valve (6) is operable to introduce gas into the water intake casing.