An Emergency Position Indicating Radio Beacon (EPIRB) is one of the most important pieces of safety equipment on any vessel. Activating it triggers a coordinated Search and Rescue (SAR) response through the COSPAS-SARSAT satellite system. Knowing exactly when to activate it, how to register it, and what happens next can save lives.
GMDSS — Global Maritime Distress and Safety System
GMDSS is the IMO framework that replaced the old Morse code radio distress system. Under GMDSS, vessels are equipped according to their Sea Area (A1–A4), and all radio watch-keeping requirements are defined by sea area and vessel type. Key GMDSS equipment includes:
- EPIRB — 406 MHz distress beacon, satellite-detected, vessel-specific registration
- SART — Search and Rescue Transponder, radar-detectable, 9 GHz
- DSC — Digital Selective Calling, automated Mayday with MMSI and position
- NAVTEX — Automated broadcast of safety information in coastal waters
When to activate the EPIRB
The EPIRB should be activated when the vessel is in grave and imminent danger — typically when the decision has been made to abandon ship. Premature activation while other options remain creates false alerts, consumes SAR resources, and results in fines. Delayed activation means rescuers don't know your position until it's too late. The EPIRB test quiz covers the decision tree for activation and the legal obligations around false alerts.