A Mayday is for grave and imminent danger to a boat or to life, such as sinking, fire or a person overboard. A Pan-Pan is for an urgent problem where there is no immediate danger to life, such as a disabled engine with no hazard close by, or a crew member needing medical advice.
Marine VHF radio has three priority calls, all made on channel 16. Using the right one tells everyone listening how serious the situation is.
- MAYDAY is the distress call. It means a vessel or a person is in grave and imminent danger and needs immediate help. Examples: the boat is sinking or on fire, someone has fallen overboard, or a crew member is seriously injured or ill. A Mayday takes priority over all other radio traffic.
- PAN-PAN (pronounced "pahn-pahn") is the urgency call. It means there is an urgent situation concerning the safety of a vessel or person, but no immediate danger to life. Examples: engine failure with the wind pushing you slowly towards a lee shore, a lost rudder, or a crew member who needs medical advice but is not in immediate danger.
- SÉCURITÉ (pronounced "say-cure-ee-tay") is the safety call, used to pass on navigational or weather warnings, such as a large floating log or a ship manoeuvring in a channel. Coastal radio stations use it before weather warnings.
A Pan-Pan call follows a similar pattern to a Mayday: "PAN-PAN, PAN-PAN, PAN-PAN. All stations, all stations, all stations. This is [boat name, three times]." Then give your position, the problem, the help you need and the number of people on board, and finish with "Over."
A situation can change. If a Pan-Pan becomes life-threatening, for example the boat starts to drift onto the rocks, upgrade it to a Mayday at once. Do not hesitate to send a Mayday when someone has gone overboard; it can be cancelled if they are recovered quickly.
If the problem is solved, call again on channel 16 to cancel, so that searchers are not sent out unnecessarily.
False or hoax distress calls put rescuers at risk and are an offence.
More in the book: Chapter 11, Safety on board