The system described is intended to fill a longstanding requirement of the submarine service for a means of communication while submerged. It consists of an assembly which includes a towable buoy, tow-signal cable, winch-nest assembly, and controls. The towable buoy, which supports the communication antennas, may be released and retrieved while under way at all operating depths. At these depths it provides vlf, hf, uhf, IFF, and ECM services and a flashing marker light, as well as loran and lf reception in strong signal areas. The system requires a minimum of hull penetration for installation. It has been in operation on the USS HARDHEAD more than 18 months and has been used in many exercises at sea. In addition to regular submarine communications service, it has been used for research purposes by the Laboratory. Although experimental in nature, it has provided much useful information and experience for future buoy system.