Abstract: A system for retreiving undersea salvage items from a sub-surface location. he system includes a flotation unit, winch, related remote control unit and a power supply mounted thereon, a winch, related remote control unit, and a power supply mounted on the support element. A cable or equivalent secured to the winch includes a retrieval harness or alternative means such as a shackle for securing the salvage item to the winch. A tether connects the system to a remote salvage tender on the surface. An adjustable and automatic stop is provided by the control unit to prevent certain types of salvage from rising beyond a desired depth or breaching the surface. Portions of the system used in magnetic mine retrieval are fabricated of non-magnetic material.

Abstract: A self-contained underwater breathing loop apparatus for an oxygen rebreather includes a breathing bag formed to act as a compliant volume and a semipermeable membrane arranged to divide the breathing bag into a first chamber and a second chamber. A breathing hose is connected between a mouthpiece and the first chamber of the breathing bag to conduct exhaust breath from the diver thereto. The semipermeable membrane is formed to allow helium in the diver's exhaust breath to pass therethrough while preventing oxygen in the exhaust breath from being transported from the first chamber into the second chamber. A relief valve in the second chamber allows helium in the second chamber to be expelled into the water. A CO.sub.2 scrubber is in fluid communication with the first chamber of the breathing bag. A helium supply in fluid communication with the CO.sub.2 scrubber for supplying helium to the breathing loop through a metering valve.