Satellite messengers and communicators
Communication
Handheld satellite devices that send and receive text messages, share your track and have an SOS button, far beyond cell and VHF range. They need a paid subscription, and their SOS goes to a private response centre rather than straight into the government satellite system EPIRBs and PLBs use.
How it works
Messengers work through commercial satellite networks. Pressing SOS sends your position to the service's 24/7 emergency response centre, which alerts the rescue agency for your area and can text back and forth with you. PLBs and EPIRBs instead use the dedicated 406 MHz Cospas-Sarsat system, need no subscription, keep their battery in reserve, and add a homing signal for rescuers.
Using it
- Keep the subscription active; one maker says SOS monitoring comes with an active plan, although some of its devices keep SOS when service is suspended.
- Fill in emergency contacts and trip notes in your online account; the response centre uses them.
- Never press SOS to test it. Use the test-message feature to confirm service, or book an SOS test with the response centre.
- Keep it charged. Most messengers are rechargeable, unlike a PLB, whose battery waits in reserve for years.
- If you cancel an SOS, one maker says its response centre can no longer message your device, so tell them first if it was a mistake.
- A messenger adds to VHF/DSC and an EPIRB or PLB rather than replacing them. Beacon makers point out that most messengers don't send a 406 MHz signal or a homing signal.
Looking after it
- Charge it regularly and fully before every trip.
- Send a test message before each trip to confirm the service is active.
- Keep the device's software and your account's emergency contacts up to date.
Troubleshooting
Messages won't send
- Move to a spot with a clear view of the sky and wait.
- Check the subscription is active; the test message confirms it.
- Charge the battery and update the software.
SOS pressed by accident
- Message the response centre through the device that it was accidental.
- Then cancel as the manual describes.
Buying a boat that has one
- Plan on your own subscription and account, and ask the maker how a used device is transferred to a new owner.
- Check how well the battery holds a charge.
Sources (4)
support.garmin.com · garmin.com · oceansignal.com · sarsat.noaa.gov
General guidance for recreational boaters, researched from the sources listed and written in our own words. Your equipment manuals, local knowledge, the Navigation Rules and a qualified instructor come first.