A thruster assembly that in addition to propulsion provides water flow to/from compartments and systems on board a vessel. In a first position, the thruster assembly provides propulsion/steering. Pivoted to a second position, operation of the thruster in a first direction draws a flow into the vessel and in a second direction draws a flow out of the vessel. The flows may be conveyed to/from compartments/systems on board the vessel via conduits in communication with a chamber having an opening through which the thruster drives the flows. The flows may be used to submerge/surface the vessel, or to provide systems cooling or serve other functions. Pivoted to a third position the thruster assembly is retracted and enclosed within the chamber to form a hydrodynamically clean exterior.