Distress and rescue

Australia coordinates search and rescue across 53 million square kilometres — roughly a tenth of the Earth's surface — from a single room in Canberra. Everything below is about making their job possible.

Beacons

A 406 MHz distress beacon is the most effective piece of safety equipment on any boat. Registration with AMSA is free, takes minutes at beacons.amsa.gov.au or on 1800 406 406, and is mandatory in many circumstances. What registration buys you is time: it lets the rescue centre pull your vessel description, the number of people normally aboard, your equipment and your emergency contacts within seconds of the alert, rather than working from a bare satellite fix.

• EPIRB — registered to a vessel, larger, often float-free, and the type that satisfies mandatory carriage rules. Transmits for at least 48 hours.
• PLB — registered to a person, small enough to live on a lifejacket, works on land, sea or air. Transmits for at least 24 hours. It may not satisfy a rule that specifically requires an EPIRB — check before substituting.
• AIS MOB beacon — not part of the satellite system at all. It alerts nearby AIS-equipped vessels within a few miles. Superb for getting your own boat back to a crew member in the water; useless if nobody is nearby. Carry one in addition to, never instead of, a satellite beacon.

GPS matters enormously. A GPS-enabled beacon gives a position accurate to around 120 metres, relayed within minutes. A non-GPS beacon relies on a Doppler fix from a passing satellite: accuracy around a five-kilometre radius, and it can take hours. Analogue 121.5 MHz beacons are no longer detected by satellite at all — if you have one aboard, it is a paperweight.

Activating by accident is not a crime, but not cancelling is expensive and dangerous for everyone else. If a beacon goes off unintentionally, call AMSA immediately on 1800 641 792.

What happens when you activate

1. The beacon transmits on 406 MHz to the Cospas-Sarsat satellite constellation, and on 121.5 MHz as a homing signal for search aircraft.
2. The alert is relayed through Australian ground stations at Bundaberg, Albany and Mingenew.
3. It reaches AMSA's Joint Rescue Coordination Centre in Canberra, staffed 24 hours.
4. JRCC checks your registration, calls your emergency contacts to verify and gather detail, and tasks a response — state police marine units, volunteer marine rescue, a rescue helicopter, or for aviation incidents AMSA's own search jets based in Perth, Melbourne and Cairns.
5. Your beacon keeps transmitting for its rated life so searchers can home on it. Leave it on.

MAYDAY — grave and imminent danger, immediate assistance required. On Channel 16:

MAYDAY, MAYDAY, MAYDAY · This is Seabird, Seabird, Seabird · MAYDAY Seabird · Position 5 miles due east of the Seaway · Sinking after striking a submerged object, estimate 15 minutes afloat · 5 metre white centre console, 3 persons on board, EPIRB activated · OVER

PAN PAN — urgency: the safety of the vessel or a person is in question, but not yet grave. Engine failure drifting toward a lee shore, a serious but not immediately life-threatening injury. Same structure, prefixed "PAN PAN, PAN PAN, PAN PAN · Hello all stations" three times.

SECURITE — safety: a navigational or weather hazard others need to know about. A container adrift, a vessel not under command, a hazard on a bar.

Hearing a MAYDAY: stop transmitting and listen. Let a coast station or a better-placed vessel acknowledge first. Only answer yourself if nobody does and you can help or relay. If you must relay for a vessel that cannot transmit, the call is MAYDAY RELAY.

The commonest failure is not over-calling — it is under -calling: hesitating to say MAYDAY when it is warranted, and losing the minutes that mattered.

Channels, DSC and MMSI

Channel 16 is distress, safety and calling — make contact there, then move to a working channel. In Australia Channel 67 is the secondary distress and safety channel and the one most volunteer marine rescue bases use for routine traffic and log-ons, which keeps 16 clear. Channel 13 is bridge-to-bridge and port operations in many harbours; 72 and 73 are general ship-to-ship working channels. The old 27 MHz band still has pockets of coverage — the SA Sea Rescue Squadron monitors Channel 88 alongside VHF — but VHF has largely replaced it on range and reliability grounds.

DSC — Digital Selective Calling — is a digital layer on a modern VHF set. Pressing the dedicated distress button broadcasts your identity and, if the set is connected to GPS, your position and the time, on Channel 70, before you say a word. Then you follow up with a voice MAYDAY on 16. It requires an MMSI, a nine-digit identity for your vessel's radio, which in Australia is allocated by AMSA (not ACMA) on form AMSA 89. This split trips people up: ACMA licenses the radio equipment and the spectrum; AMSA issues the identity used for DSC and beacon registration.

Offshore, HF remains relevant. AMSA has directly operated 24-hour HF distress monitoring since 1 January 2022, watching 4125, 6215, 8291, 12290 and 16420 kHz, and broadcasting maritime safety information over the same network.

Log on, log off

Australia's volunteer marine rescue organisations run a free trip-notification service, and using it is the cheapest safety measure available. You give them your vessel, the number aboard, where you are going and when you expect to be back. If you do not log off, they call you; if they cannot reach you, they start looking. It costs nothing and it is the difference between a search that starts at dusk and one that starts the following afternoon.

• NSW — Marine Rescue NSW, via the free app (which offers live tracking with position updates every 30 minutes) or VHF 16 to a local base.
• Queensland — Marine Rescue Queensland, formed on 1 July 2024 by merging 27 VMR squadrons and 19 Coast Guard flotillas into one statewide service under the Queensland Police Service. Older references to "VMR" and "Coast Guard Queensland" as separate bodies are now historical.
• Western Australia — Volunteer Marine Rescue WA under DFES, now using the Deckee app alongside traditional radio call-in.
• South Australia — SA Sea Rescue Squadron, monitoring VHF 16 and 67 and 27 MHz Ch 88, 7am to 7pm — worth knowing before an early or night departure.
• Tasmania — a state VHF repeater network with TasMaritime Radio handling broadcasts and relays.
• Victoria — coordinated through Victoria Police and Emergency Management Victoria, with several volunteer providers; the sector has been under active reform, so check the current arrangements locally.