US Patent 7819711 Retractable thrust reversing bucket for boat propeller

A thrust bucket for use on a boat propeller including a plenum and a positioning system. The plenum includes a plenum wall with at least one water flow valve located on the plenum wall. The positioning system moves the plenum between inoperative and operative positions. The thrust bucket may include an annulus positioned in close proximity to a swept radius of the propeller when the plenum is in the operative position. The at least one operable water flow valve may be controlled to control a direction of water departing the plenum, or to control a quantity of water flow out of the plenum. The thrust bucket may further include a propeller guard mounted to the plenum and positioned at an inlet side of the propeller.