Over the past decade ROV usage has increased dramatically in world wide marine fields in inspection, debris removal, object retrieval, and other usages. With this expanded use has come similar dramatic new technology for the vehicle systems. This extends the vehicle operational capabilities and gets more power into a very small package. This entire 400 Hz powered hydraulic propulsion system weight (including all items such as thrusters, motor, pump, valves, etc.) is equal to just the electric motor/pump package of existing 60 Hz powered systems.To obtain higher vehicle performance in a smaller package, higher power voltages and frequencies are used. A high speed electric motor driving a miniature variable delivery hydraulic pump for the propulsion system produces 10 HP in a 16.6-1b. package. Similar size and weight reductions are made in the thruster motor/servo valve packages. These small vehicles may not need a dedicated support vessel.