Abstract: A combined digital depth control and rate of ascent control device to be used by scuba divers. The device would automatically prevent the diver from exceeding a predetermined depth and prevent the diver from ascending at an excessively high rate. The device comprises a sealed housing attachable to the apparatus so as to be submerged in the water with the diver. The housing has an inlet connectable to the pressurized gas tank, an outlet connected to the inflatable buoyancy jacket, a control passageway between the inlet and outlet, being automatically displaced to open the passageway upon sensing the predetermined depth.

Abstract: A raft knife and pocket structure to be fixed to a raft, such as an inflatable aircraft, and which is for use in severing a main tether between the raft and an aircraft, and which is composed of a pocket structure adapted to be fixed to the raft and in which pocket structure, which includes flaps which open and close and are adapted to close about a knife, there is a knife which is buoyant and which includes a recess which is spanned by a blade for use in cutting the raft from the main tether connecting it to an aircraft.