Recent advances in magnetic materials, cooling and design allow simplification of compa ct propulsion motor driv es for naval ship drives. The paper shows the advantage of direct water cooling with integrated gate commutated thyristor (IGCT) variable speed drives to lower the overall weight as well as the manufacturing cost of these propulsion plants. The drives can be installed as a hy brid electric drive or as an auxilia ry propulsion plant connecte d to the main reduction gear on a surface ship. A trade study sho ws the advantage of going to a mediu m voltage (4160 to 7000 Volts AC) on the propulsion machine and power electronic drive when the horsepower ratings exceed 2500 HP. A preferred ci rcuit is an AC Resonant Link with an input total harmonic distortion of 1.5%.