Hydraulic systems are used on marine vehicles for steering, vehicle control, and utility services. System components that generate and transmit noise are of concern. This SAE Information Report (a) addresses noise requirements which may apply to the hydraulic systems of ships and submersibles, and (b) identifies noise sources and techniques which may be used to reduce system noise. Noise of power sources (e.g., electric motors) and end items (e.g., steering linkages) is beyond the scope of this document.