What is Communication Systems (EPIRB, Satellite, SSB, AIS, VHF)?
A comprehensive emergency communication suite relies on multiple redundant systems, each with unique capabilities. An EPIRB, or Emergency Position Indicating Radio Beacon, is a satellite distress beacon that alerts international rescue authorities and transmits GPS position when activated.
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What it is
A comprehensive emergency communication suite relies on multiple redundant systems, each with unique capabilities. An EPIRB, or Emergency Position Indicating Radio Beacon, is a satellite distress beacon that alerts international rescue authorities and transmits GPS position when activated. Satellite communicators, such as InReach devices, provide two-way text messaging, tracking, and SOS alerts. SSB, or Single Sideband radio, is a long-range communication system often used for weather routing and offshore calls. AIS, or Automatic Identification System, broadcasts your vessel’s identity, position, and movement to other vessels and shore stations. VHF radio is a standard short-range marine radio for ship-to-ship and ship-to-shore communication. Personal AIS beacons are small wearable devices that activate when a person goes overboard, transmitting their position via AIS to the vessel’s chartplotter and nearby receivers. Personal Locator Beacons, or PLBs, are portable devices that transmit an SOS signal and GPS location to emergency rescue authorities when activated.
What it does
EPIRBs automatically send distress alerts with your position, can be registered to a vessel, activate upon contact with water and are buoyant. Satellite communicators allow two-way text messaging and SOS alerts, enabling coordination with rescue centers or shore contacts. SSB radios enable long-range communication (hundreds to a few thousand miles, depending on propagation). AIS continuously broadcasts vessel position for collision avoidance and safety messaging. VHF radios provide local communication depending on antenna height and standardized distress calling. Personal AIS beacons immediately alert the vessel when a crew member goes overboard, displaying the person’s position on the chartplotter and nearby vessels’ AIS displays, typically within a ~3–5 mile range under normal conditions. Personal Locator Beacons are similar to EPIRBS, but must be manually deployed and do not float.
Why it matters
In emergencies, rapid communication of position and distress is critical. Different systems cover different ranges and functions. No single system works in every scenario, so redundancy ensures communication is possible if one fails.
General Maintenance
EPIRBs should be tested annually, or according to the manufacturer’s instructions, by placing the device in a bucket of water to confirm it is transmitting a signal. This test may only be performed during designated testing periods. Check with your local U.S. Coast Guard office for current regulations and approved testing times. Maintenance schedules vary for each communication system, so always follow the manufacturer’s guidelines. Keep registration information current with accurate vessel and contact details, replace or service batteries as recommended, maintain active subscriptions, update firmware, check battery condition and periodically test messaging and functionality where applicable.
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