MAYDAY, PAN-PAN and SÉCURITÉ are three words a cadet memorises in five minutes.
Choosing the right one, with the situation degrading and the vessel moving, is another matter.
The three levels
The definitions leave no room for doubt. They are three grades of priority, highest first:
MAYDAY — distress. Grave and imminent danger. Immediate assistance required. The vessel is sinking, there is a fire on board, someone has a medical emergency that cannot wait.
PAN-PAN — urgency. A real urgency concerning the safety of the vessel or a person, but without grave and imminent danger. The engine is gone and the boat is drifting, steering has been lost, there is a failure that does not yet threaten buoyancy.
SÉCURITÉ — safety. An important warning for others: a dangerous object adrift, a meteorological warning, a change in navigational marks. It does not ask for help; it offers it.
The difference between MAYDAY and PAN-PAN is not the severity of the failure. It is imminence. A contained galley fire may be PAN-PAN; the same fire spreading is MAYDAY. Same vessel, same fire.
How each one is transmitted
All three calls are transmitted three times and on channel 16 (156.800 MHz), the frequency for distress, urgency, safety and calling.
After the word repeated three times comes the vessel’s identification, the position, the nature of the problem and the assistance required. That structure is not a formality: it exists so the coordination centre can dispatch without having to ask, and so any vessel keeping watch understands within ten seconds whether it can help.
SÉCURITÉ has a particularity: it is normally announced on 16 and the full message is transmitted on a working channel, so a potentially long warning does not occupy the distress frequency.
The mistake is not confusing them. It is hesitating to escalate
In a simulation exercise, the mistake is almost never not knowing the definition. The cadet knows it, repeated it in class, could write it out.
The mistake is staying one level below. The situation keeps degrading and the cadet remains on PAN-PAN because saying MAYDAY feels like an overreaction, or because they fear it is not “that bad”, or because triggering distress feels like a commitment there is no coming back from.
By the time they finally say it, they have lost minutes they did not have.
Escalating is reversible. Not escalating is not
Here is the point that is almost never taught, and that resolves the hesitation:
If a MAYDAY has been transmitted and the situation resolves, it must be cancelled. There is a procedure for that, and using it is not a failure: it is part of the system. The alert is cancelled, the frequency is released and rescue assets become available again.
The minutes lost by not escalating in time, on the other hand, cannot be recovered by any means.
The two options are not symmetrical, and that asymmetry is what a cadet needs to understand before stepping aboard. Not so they shout MAYDAY at every problem — a false alert has a cost and consumes real resources — but so they know that the decision to escalate can be undone and the decision not to escalate cannot.
The question to teach
The useful question is not “what happened to me?”. Classifying the failure settles nothing, because the same failure can be PAN-PAN or MAYDAY depending on how it develops.
The question is: “is this going to get worse, and how much time do I have?”
If the answer is “yes” and “not much”, it is MAYDAY. If it is “yes” but there is margin, it is PAN-PAN and it needs watching, ready to escalate. If the answer is “no”, it is probably neither.
How this looks in a simulation exercise
In a scenario, the hesitation shows with a clarity no lecture achieves. You can see the exact minute the situation stopped being an urgency and became a distress, and compare it with the minute the cadet declared it.
That gap, measured in minutes, is the lesson. It is not corrected with one more slide: it is corrected by letting the cadet choose wrong where nobody dies, and then showing them in the debriefing the full record of what happened while they hesitated.
What this means for training providers
A programme can teach all three definitions in one class and test them in a written exam with perfect results. That does not mean the cadet will choose well under load.
The gap between knowing and deciding only closes with repetition in an environment where the mistake has visible consequences and no casualties.
MAYDAY, PAN-PAN, SÉCURITÉ. Three times, on channel 16. And the same question every time: is this going to get worse, and how much time do I have?
Advenio Software develops maritime safety solutions: GMDSS training simulators, coastal radio station software and nautical training tools, for both the professional and the recreational sector.