How to Make a VHF Mayday Call on Channel 16

The Coast Guard reserves Mayday for a distress situation involving grave and imminent danger. Channel 16 is the international voice distress, safety, and calling channel monitored by the Coast Guard and other vessels within radio range.

A VHF is primarily line-of-sight and its usable range depends on antenna height, power, terrain, and installation. Do not promise coverage from a distance merely because the radio powers on.

Select Channel 16, use high power unless circumstances call for otherwise, key the microphone, and clearly say “Mayday” three times followed by the vessel name and call sign. Give the position, nature of distress, assistance needed, and number of people aboard.

Add a vessel description and any other information that will help responders. Release the transmit button to listen for a reply, and repeat the call if necessary.

Write the call sequence, vessel name, registration or call sign, and radio controls on a waterproof card. In an emergency, a passenger may need to make the call while the operator handles the boat or an injured person.

Keep the current position source visible. A correct position is more useful than a vague landmark, but provide both when doing so will help responders understand the location.

Learn channel selection, power level, squelch, volume, and microphone operation without transmitting a Mayday. Use an approved radio-check method rather than Channel 16 for routine checks.

Pair voice knowledge with DSC setup when the radio supports it. A properly registered MMSI and a working internal or connected GPS can add identity and position to a digital distress alert.