Abstract: The swim fins (10) each include a molded center guide (14) and a shoe portion (12). A first wing (16) is pivotally attached to one side of the center guide (14) by a hinge member (18). A second wing (20) is pivotally attached to the other side of the center guide (14) by a hinge member (22). The hinge members (18, 22) have a flexible web (50) and flanges (52, 54). One of the flanges (54) of the hinge (18) is inserted into a hinge bead retainer slot (24) in the center guide (14) and the other flange (52) is inserted into a hinge bead retainer slot (38) in the wing (16). One of the flanges (52) of the hinge (22) is inserted into a hinge bead retainer slot (26) in the center guide (14) and the other flange (54) is inserted into a hinge bead retainer slot (40) in the wing (20). Stop surfaces (42, 44, 46, 48) on the wings (16, 20) cooperate with stop surfaces (30, 32, 34, 36) on the center guide (14) to limit pivotal movement of the wings relative to the center guide.

Abstract: A system whereby the air pressure from the scuba diver's tank is reduced in pressure and is available to blow a horn. When not submerged the horn can be heard for a long distance, up to a mile or more. When in the water the horn produces vibrations and noise which can be detected for a hundred yards or more.