EMERGENCY DISTRESS SIGNALING DEVICES.

A study was made of some of the factors involved in providing suitable emergency distress signaling devices to aid in the location of lost personnel or vehicles. One factor particularly considered was a suitable source of electrical power. The magnesium sea-water battery with tunnel diode converter is proposed as being particularly applicable as a power source for marine environments. With the possible exception of size and weight this power source would best meet the following requirements low cost, reliability, indefinite shelf life, small size and weight, ruggedness, capability of automatic activation, and adequate lifetime for location by search parties. Several typical devices using sea-water batteries with tunnel diode converters were devised, including an audio device to be located by sonar-equipped search vessels, a visual flashing light device, and three radio transmitters to transmit SOSs or audible tones. Considerations of the three radio transmitters indicate a preference for vhf operation. Although developed primarily as distress signaling devices, some of the devices might also be useful as markers for marine buoys or small boats or as navigational beacons. Author