Abstract: A life-saving appliance that automatically inflates an inflatable tube after a short period of contact with water comprising a metallic receptacle containing a refrigerant in the liquid stage, a membrane normally sealing the receptacle, a manually-actuated pin for penetrating the membrane, an inflatable tube surrounding the receptacle, a conduit for connecting the interior of the receptacle to the tube, and a water-soluble retaining band for holding the tube, in deflated condition, against the exterior of the receptacle. The appliance is compact in its normal, unactuated condition and can be thrown several feet outwardly over a body of water with significant accuracy; shortly after contact with the water, the retaining strip disintegrates and the refrigerant passes through the membrane, which has already been punctured, to rapidly expand and fill the inflatable tube.