GPS rescue device are really great but a bit different than the subject of the post because you may have one and your partner may have one but they may not be much help in you finding each other. Some good info on the InReach Communicator and Spot on a previous thread http://www.detectorprospector.com/forum/topic/14-delorme-inreach-satellite-text-communicator/ and some more on the ResQlink at http://www.detectorprospector.com/forum/topic/1568-resqlink-emergency-locator/