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Man Overboard – MOB

Man Overboard (MOB) – as you will see there is not a “hard and fast rule” but more of a judgement call at the time of the incident.

There is much confusion, among recreational mariners, regarding the correct use of radio during Man Overboard (MOB) emergencies at sea. Some organisations and groups, representing various sectors of the industry, favour MAYDAY over PAN PAN and are actively promoting their own views among their members.

Conflicting advice and different interpretations of official guidelines have further fuelled the confusion. Such confusion may indeed lead to undesirable outcomes during MOB emergencies, possibly exposing the well-meaning advisors to unwelcome liabilities.
The following is an attempt to provide a more informed basis for the crucial decisions that mariners must take when someone is lost overboard.

Little knowledge is dangerous!

Let us first test our understanding of the rules by answering a simple question:
Which of the following is the most important?
If you selected MAYDAY, you have failed the test!
MAYDAY signal is used during distress situations indicating that:
“A mobile unit or person is threatened by grave and imminent danger and requires immediate assistance”.
In other words, it is too late to do anything to avoid the danger. SECURITE signal, on the other hand, is used to announce safety messages that help mariners avoid danger in the first place!
To say MAYDAY is more important than SECURITE is to claim that cure is better than prevention. The same observation applies to PAN PAN.
All three signals are important and must be given equal attention at all times. Their difference is in their priority for transmission. That is to say if a SECURITE, a PAN PAN and a MAYDAY are to be broadcast at the same time, MAYDAY goes first. That is all. No more, no less.

Clarity saves, confusion kills.

The statement above is self-evident and needs no further explanation. To ensure clarity, MAYDAY calls have a strict prescribed format that must be followed to the letter. The response to a MAYDAY call is also strictly prescribed and is legally binding.
The correct format for MAYDAY transmission is as follows:
This is
Titanium, Titanium, Titanium
Position 42˚ 29’ South, 117˚ 19’ East
16 POB

This format ensures that information critical to successful search and rescue, is broadcast in the correct order of who, where, what (after attracting everyone’s attention).
During distress situations, the ability to transmit radio signals is lost as soon as the battery is submerged. The prescribed order for transmitting information, ensures that more important
information (where) is broadcast before (what) just in case the battery submerges in the middle of a call for help.
The obligation to accept distress calls is absolute and they must be given priority over all other communications. This is the law! No If(s), But(s) or Maybe(s)!
In practice, a MAYDAY call will effectively lock out all other transmissions until such time as the search and rescue effort is well underway, and even then, only important calls are allowed.
More importantly, all stations must stay tuned on the emergency channel and record the details of distress radio traffic in their radio log even if they are not in a position to render assistance.
And there is more! The stations that are able to help, must help. This is also the law. In most cases, nearby vessels will rush to the position broadcast during the distress call to render assistance.

First come first served.

Imagine a beautiful busy late afternoon on Sydney Harbour or the Derwent River with hundreds of vessels on the water. Vessel A with two persons on-board (2 POB) crossing a traffic lane loses its steering and is drifting onto rocks. It decides to send a MAYDAY call to warn a large vessel using the lane (but still some distance away) and at the same time ask for immediate assistance.
A few minutes after vessel A transmits its MAYDAY, two other vessels B and C collide with B sinking fast and C on fire. The skipper of vessel B with 6 POB decides to send a MAYDAY. Skipper of vessel C with 8 POB does the same. The three vessels have given different positions obtained from their respective GPS systems. With three MAYDAY calls on the same frequency at the same time, we now have a very confusing situation and confusion kills.
Technically, the first vessel to declare emergency (A) has the control of the distress frequency.
Instead of calling MAYDAY, vessels B and C may indeed achieve better results by using flares or other means of declaring emergency such as Digital Selective Calling (DSC) if available.
The chances of more than one MAYDAY situation developing at any given time is actually higher that we may think. Just remember the Sydney-Hobart Race of 1998.

By using MAYDAY, vessel A has locked-out the distress frequency yet it carries 2 POB compared to 14 POB on the other vessels. Nevertheless, Vessel A has the same rights to radio frequencies as the other two and cannot be blamed for exercising its rights. Besides, vessel A could not have predicted the second incident.
The question is, could vessel A have achieved the same outcome by using PAN PAN instead? If not then it made the right call. Otherwise, it would have been more prudent to use PAN PAN and leave the higher priority available to others who may have needed it more. Remember you could be a person on-board B or C.

The boy who cried wolf.

The definition of distress, “a mobile unit or person is threatened by grave and imminent danger and requires immediate assistance”, implies that all other efforts to remedy the situation have failed and the last resort, a MAYDAY call, must be used. This is a judgement call. Repeated overuse of MAYDAY, for more manageable situations, may indeed cause it to lose efficacy and reduce its effectiveness.

Come here or go away?

Let us consider the following scenarios:
1- A person falls overboard a yacht. Others on the boat witness the fall and can see the person in the water. The skipper is manoeuvring the boat to go to the rescue and retrieve the person.
The last thing the skipper needs is a dozen well-meaning good Samaritans in fast boats with powerful engines applying full power, throwing big wakes behind them, and racing at break-neck speed to the position broadcast in the MAYDAY call. They could run over the person in the water!
In fact if this happens during a yacht race, all of the yachts following (more or less on the same track) should immediately disperse to avoid running over the person in the water.
Besides, is the broadcast position that of the person in the water or the vessel itself? Remember, confusion kills!
2- What if we lose sight of the person in the water and want all vessels in the vicinity to stop their engines or slow down and keep a good lookout to find that person or, more importantly, avoid running over that person? Well, same as in previous example, a MAYDAY call may actually make things worse by creating confusion. In this scenario, the MAYDAY must also be modified to provide approximate position of the person in the water. This may not be clear to those who copy the distress call. A MAYDAY call is simply not flexible enough for this purpose!
3- What if someone falls overboard without being noticed and several hours pass before someone realises that the person is missing? Use of MAYDAY would be even more confusing. What position should be reported in the distress call? Will those who copy the call actually realise the approximate nature of the position or simply hear what they expect to hear (in a MAYDAY call) not what is being said? Would they do what is asked of them or simply head to the reported position at maximum speed? More importantly, would PAN PAN achieve the desired outcome?

Leaving one’s options open

It is very easy to upgrade a PAN PAN to a MAYDAY. It is almost impossible to do the reverse without causing confusion and confusion kills.

There is no substitute for intelligence and sound judgement.

A Man Overboard (MOB) situation is one of the most traumatic events on-board any vessel.
Nevertheless, it is not always a MAYDAY situation. It is not always a PAN PAN situation either.
Sometimes, it is not even an emergency! There is no clear-cut choice between MAYDAY, PAN PAN or even SECURITE for Man Overboard.

If there was a clear-cut choice, the regulators would have prescribed it.

Although the regulations lean towards the PAN PAN call from a ship as the preferred choice for MOB situations, there is nothing to stop skippers declaring distress if they judge it to be more appropriate.
However, as we have discussed above, over-simplification of a “one size fits all” response, may actually have the opposite outcome to what was intended and those who prescribe it may be blamed for any adverse results.


The choice of MAYDAY or PAN PAN for Man Overboard (MOB) situations is a judgment call made by the skipper at the time of the incident. In making the decision the following points are worthy of consideration.
• MAYDAY (Distress priority), PAN PAN (Urgency priority) and SECURITE (Safety priority) have the same importance and must be given the same attention! They only differ in their priority for broadcast (if they happen at the same time).
• Distress communications shall have absolute priority over all other transmissions.
• Urgency communications shall have priority over all other communications, except distress.
• Safety communications shall have priority over all other communications, except distress and urgency.
• It is always prudent to use the lowest priority that achieves the desired results leaving the higher priorities available for someone else who may be in more danger (you may be that someone else).
• It is easier to upgrade a PAN PAN than to downgrade a MAYDAY!
• If you want someone to stay clear of a person in the water, MAYDAY may not be the best call!
• Do not rely on hearsay and well-meaning advice. Use your own judgement.
• “One size fits all” solutions are not suitable in life and death situations.
• Nothing stops you using a MAYDAY if you think it is a right thing to do. Ask yourself if PAN PAN can achieve the same or better results (less confusion).
• In many MOB cases, a vessel can start with a PAN PAN and later upgrade it to MAYDAY if necessary.

Epilogue and Disclaimer

No doubt some would disagree with what is presented here and the arguments for and against the choice of priority signal will continue. The purpose of this brief is to provide some food for thought for skippers who must make the final call.
This document does not seek to prescribe any set radio procedures for MOB. Relevant Australian and International regulations in the matter have the final say.

Discussion Paper presented by Sam Josof – AMC OMC Manger: Man Overboard