Oh my goodness - there are a lot of errors in the information above.

1) Contemporary Emergency Personal Locator Beacons work on 406 MHz only. 121.5 MHz is generally reserved for aviation use only. There was a very early generation of personal beacons that worked on 121.5, but they were pretty clunky devices, sort of like the very first generation of 'brick' cell phones. I don't think they are sold anymore.

2) The beacons don't require an internal GPS. The location of the beacon is determined by triangulation (doppler shift) when the satellite passes overhead and picks up the signal from the beacon. Some beacons contain a GPS unit, to increase the precision of the location.

3) The satellite constellation that picks up the beacon signals (COSPAS-SARSAT) will report reception of a signal to the country in which the beacon is registered. It is then up to the appropriate organization in that country to take any subsequent action. Aviation signals are handled differently than personal beacon signals. You might want to determine which 3rd world countries even participate (meaning, have a functioning SAR infrastructure), before you spend your money...

4) In most cases, the cost of the rescue effort (assuming one is launched) is borne by the folks holding the beacon. There are exceptions, for example, if you are a member of REGA in Switzerland, or if the government of the country you need rescue in is particularly benevolent (e.g. Canada). If you choose to have a third party organization notified (e.g. a rescue organization other than one operated by the government of the country you are in when you get into trouble), then the cost of the rescue will be entirely to your own account.

Do the research first, before you buy one. This website is an excellent place to start: http://www.cospas-sarsat.org/MainPages/indexEnglish.htm

[This message has been edited by PanEuropean (edited 27 February 2005).]