It is an a ResQLink PLB-375 (part number 2880), made by ACR.
Its one of those things that we hope to never have to use. Its sole purpose is to call for help from Search and Rescue by sending your GPS position to a satellite system when activated. It’s small and light and easy to use. Unclip the antenna so that it is vertical and push the ON button.
WARNING: This PLB is authorized for use only during situations of grave and imminent danger. It is only to be activated when all other means of self-rescue have been exhausted. Deliberate misuse may incur a severe penalty.
In other words, try your cell phone and/or VHF radio first if at all possible.
There were several options that the club considered. All use a satellite system for communication; some have additional, very desirable features and higher costs.
PLB. “SOS” feature only. Uses the COSPAS-SARSAT satellite system
These beacons must be registered with the government, but there is no monthly or annual usage charge. It uses a 5 Watt 406 MHz signal to send the distress signal to the satellites.
ACR makes several models and there is also the McMurdo FastFind 220.
SPOT2, SPOT3, and Delorme inReach. In addition to the SOS feature, these units also can send “I’m okay” messages to selected contacts, they can send periodic position reports so that your friends can follow your track on a map on a web page, and they can also send “send help” messages to your selected contacts instead of to search and rescue. These are desirable features, but they come at a cost of at least $100 per year, which is more than the club can afford. Both Spot and inReach use the commercial satellite phone systems. Spot uses the Globalstar satellites and inReach uses the Iridium satellites; both systems use low earth orbit satellites. The satellite system can do two-way communication, but these devices can only send pre-written messages; they cannot receive messages.
SPOT Connect and inReach Smartphone. These devices can do all of the above, plus they can be used together with an app on your smartphone. You can write a short text message on the spot and you can receive messages. This is a very nice feature, and it comes at an additional expense. The inReach SE is similar, except that it is stand-alone; it does not require a smartphone.
Two way communication will obviously dominate in the future. If you ask for help, it’s nice to say what kind of help you need. It’s nice to have confirmation that help is on the way. From the SAR’s point of view, it’s nice to know that it is not a false alarm.
Satellite Phones. These have been expensive to buy and expensive to use.
SPOT makes one now which is more affordable. Relatively speaking.