As the technologies available for SAR alerting continue to develop and grow, so too has confusion regarding the capability and limitations of related safety devices, including those that also use the term, “beacon”
Avalanche tranceivers are critical safety devices that should be worn by people working, travelling, or recreating in avalanche-prone areas. Since survival after being buried in an avalanche is usually measured in minutes, rescue must be carried out by other people close by who were not buried. By homing in on the signal transmitted by an avalanche tranceiver, those who are buried can hopefully be located and dug out, before they run short of breathable air.
These tranceivers should not be confused, however, with 406 MHz COSPAS-SARSAT beacons like PLBs, ELTs, and EPIRBs, or any of the alternative locating devices currently on the market. Avalanche transceivers cannot be detected by COSPAS-SARSAT satellites, overflying aircraft, or even heard by the human ear. They are not designed, nor are they suitable for distress alerting.
Family Radio Service (FRS) & General Mobile Radio Service (GMRS) radios and beacons
These popular portable radios are now used in virtually every outdoor activity, and are an easy and effective means of maintaining short-range communications within members of the same group. However, FRS and GMRS frequencies are not universally monitored by emergency services personnel. While some parks and resorts have designated certain FRS and GMRS channels for emergency purposes, the public should not have any general expectation of being able to send a distress message using these radios. They should not therefore be relied upon as an emergency communications device.
Similarly, emergency beacons that transmit on FRS or GMRS frequencies are not monitored by search and rescue authorities, unless there is specific information that a distress situation exists, and that an FRS/GMRS beacon is being used. As these FRS/GMRS beacons are very rare, few search and rescue teams are equipped or trained to locate them.
Maritime Survivor Locator Devices (MSLDs)
Maritime Survivor Locator Devices, or MSLDs, are short-range beacons most commonly used by personnel working on ships or offshore oil and gas platforms. They are compact beacons worn on a lifevest or floatation suit, and may be manually or water-activated. Transmitting a low-powered radio signal (e.g. 121.5 MHz), MSLDs are intended for short-range homing. Frequently called “man overboard” beacons, they indicate the direction towards a person who has fallen into the water, which is particularly useful during rescue operations in heavy seas or darkness. MSLDs are not, however, designed or intended to be a primary distress alerting device, nor are they required to meet the minimum standards for a COSPAS-SARSAT PLB or EPIRB.