Sentence:  A pump unit for a <WSD>motorboard</WSD> having a screw disposed in the water when the motorboat is in the water, the screw constituting a propeller for moving the boat along in the water and constituting an impeller when the pump unit claimed hereinbelow is applied thereto, the motorboat also having a structure mountin the screw, the axis of rotation of the screw determing a longitudinal direction extending fore and aft... 
Meaning of the word marked with <WSD> tags:  An outboard motor.