Are 406 MHz EPIRBS/ELTs/PLBs a component of GMDSS?

• A. Yes
• B. No
• C. Only EPIRBs
• D. Only PLBs

Answer: (A)

The essential idea is how distress alerts are sent and shared in GMDSS. Beacons operating at 406 MHz—whether labeled EPIRB, ELT, or PLB—play the satellite-based distress-alerting role that underpins GMDSS. When a 406 MHz beacon is activated, it transmits a digital distress signal that includes a unique beacon identifier, and, if properly registered, vessel or personal data. This signal is picked up by the COSPAS-SARSAT satellite network and quickly relayed to the appropriate maritime Rescue Coordination Center (MRCC). Because the message includes identifying information, responders can locate and assist the person or vessel much faster, even from remote areas where no coastal stations are in range. The 406 MHz satellite component complements the shore-based elements (like VHF DSC and MF/HF signaling) and is why these beacons are considered part of GMDSS. The older 121.5/243 MHz beacons still exist for visual homing, but the key, modern distress-alerting capability comes from the 406 MHz system.