A Sea-Powered Radio Beacon with Extended Storage and Operating Capabilities

Submarine Emergency Position Indicating Radio Beacons (SEPIRB) are carried aboard all submarines to send an emergency signal if a submarine is trapped on the bottom and unable to surface. Currently they use primary lithium batteries for power which have a limited shelf life limiting the life of the buoy. At the same time the amount of data transmitted is limited. The sea is an active environment, with a deployed buoy in constant motion. Harnessing this motion to generate electrical power is the key to a system with a much longer storage life. We propose to harness this motion using a polymer based electrochemical system. The polymer system is superior to a tradition piezoelectric because it offers a better frequency and potential match. Piezoelectric systems are efficient at high frequencies, but wave energy is only available at frequencies under 1 Hz where the polymer systems are much more effective. This will be combined with an improved electronics package to increase the amount of information transmitted. The system proposed here will include a storable seawater battery for fast starting and be deployed from the same 3” system as the current buoys. These features make adaption of the improved buoy relatively simple.