an electric autoinflator for inflating inflatable devices such as personal flotation devices , life rafts , buoys and emergency signalling equipment . the electric autoinflator comprises an actuator assembly including a fusible link . a water - sensing electrical circuit and battery supplies electrical current to the fusible link actuator assembly upon immersion in water for a predetermined period of time . upon fusing of the link , the actuator assembly forcibly causes a firing pin of the inflator to pierce the frangible seal of a compressed gas cartridge . the escaping gas then inflates the inflatable device .