Modern Americans are so used to cell phones in case of emergencies that we forget systems have been in place for years to help aid people when in distress or emergencies. Pilots use emergency locator transmitters (ELTs) and there are personal locator beacons, or PLBs, for land distress signals. Another name for these is a distress radio beacon.
Boaters use the emergency position indicating radio beacon (EPIRB) to signal distress in maritime emergencies. When EPIRBs are activated and begin to transmit radio signals, they also transmit the exact location of the EPIRB as well. All EPIRBs should be designed to be waterproof and buoyant -- so that if a ship sinks, the EPIRB floats on the water above the wreckage. Of course, it needs to be located outside the cabin.
Older models of the EPIRB do not have GPS systems, and as a result do not send out the exact coordinates of their locations. Instead, an older model sends only its serial number, which is then tracked by various satellites to a general location. It takes a much longer time to pinpoint the location of the older models and therefore make a rescue. Many older models transmitted only low-power analog signals as well.
As of February 1, 2009, the International Cospas-Sarsat Programme phased out category B (also called "mini-B") EPIRBs that had to be manually activated [source: National Oceanic and Atmospheric Administration]. Boaters should upgrade to the newer EPIRBs that can be detected by GPS and run on 406 megahertz instead of 121.5 MHz.
No matter which beacon a boater chooses, it is important to ensure that it meets the needs of the boater and that the owner registers the beacon -- registration helps rescue services find distressed boaters more quickly in an emergency than if the EPIRB is not registered [sources: National Oceanic and Atmospheric Administration, Cospas Sarsat]. It also helps to become familiar with beacon operation and to follow recommendations from the manufacturer on EPIRB maintenance and self-testing.
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