Aquarious water propulsion dual impeller pump

A marine water jet propulsion system comprises a pump having an inlet (6, Fig 1) and an outlet (2, Fig 1). The pump comprises an outer housing 2A and a pair of parallel drive shafts 7A mounted within the housing, such that in use they lie one above the other and perpendicular to the flow of water through the pump housing. The lower drive shaft is driven by an electric motor and is linked to the upper drive shaft by a geared power transmission means (3D, 6D, 8D, Fig 5). Each drive shaft is provided with a plurality of radially extending vanes 3A for driving the water through the housing and arranged such that each vane as it rotates is in sealing contact with an inner wall 1A of the housing. The drive shafts are spaced apart such that the vanes on each shaft intermesh at the centre of the housing. The pump may be operated in a forward or reverse direction for use within a vessel water jet propulsion