There is actually a standard [0] and devices that meet this standard you can buy from places like REI [1]. That will send alerts/help and get you found. They re

There is actually a standard [0] and devices that meet this standard you can buy from places like REI [1]. That will send alerts/help and get you found. They require no monthly fees, etc. You can also buy "fancy" ones like the spot [2], that don't generally meet the standard but allow you to send messages besides "EMERGENCY". [0] https://en.wikipedia.org/wiki/International_Cospas-Sarsat_Programme https://en.wikipedia.org/wiki/International_Cospas-Sarsat_Pr... [1] https://www.rei.com/c/personal-locator-beacons?r=c&ir=category%3Apersonal-locator-beacons&page=1 https://www.rei.com/c/personal-locator-beacons?r=c&ir=catego... [2] http://www.findmespot.com/en/ http://www.findmespot.com/en/