Mayday - MOB - Number of Persons Aboard

laika

laika

Well-Known Member
Joined
6 Apr 2011
Messages
8,307
Location
London / Gosport
Visit site
I like to think myself reasonably well versed in radio procedure and not too shabby in most safety-related yacht things so I feel deeply ashamed to confess that I am ignorant on an important point which intermittently bothers me.

When calling mayday for a MOB, is the casualty included in "number of persons on board"?

In practice I would doubtless deviate from standard procedure with something like "1 casualty in the water, 2 persons still aboard".

I occasionally try to google this but have been unable to turn up anything definitive. Plenty of mayday templates on line which state "I have ... Persons aboard" but all the examples seem to be "sinking". Yesterday I decided to mail the RYA (hoping they don't strip me of my certificates for asking) but got an automated reply that they're on hols til next week.

Mostly this is just "something I should know but don't" but "2 persons on board" is a markedly different situation if that 2 includes the one in the water.

I'm sure plenty of people have an opinion on this but can anyone point to a reference where this is written down?
 
laika said:
I like to think myself reasonably well versed in radio procedure and not too shabby in most safety-related yacht things so I feel deeply ashamed to confess that I am ignorant on an important point which intermittently bothers me.

When calling mayday for a MOB, is the casualty included in "number of persons on board"?

In practice I would doubtless deviate from standard procedure with something like "1 casualty in the water, 2 persons still aboard".

I occasionally try to google this but have been unable to turn up anything definitive. Plenty of mayday templates on line which state "I have ... Persons aboard" but all the examples seem to be "sinking". Yesterday I decided to mail the RYA (hoping they don't strip me of my certificates for asking) but got an automated reply that they're on hols til next week.

Mostly this is just "something I should know but don't" but "2 persons on board" is a markedly different situation if that 2 includes the one in the water.

I'm sure plenty of people have an opinion on this but can anyone point to a reference where this is written down?
Click to expand...
You could just use your common sense. ?
 
NormanS said:
You could just use your common sense. ?
Click to expand...

Hence the "In practice I would..." and if I had no clue I wouldn't have waited this long to find out.

But we have procedures to standardise things so that everyone doesn't use their own, variable "common sense". A mayday procedure we all recognise exists. Hopefully we all know it by heart. It's just a minor niggle what those publishing these templates expect "..." should be in "I have ... persons on board" in the case of an MOB.
 
According to my short range course, the number should be all people aboard the boat before the incident started, including any casualties and the person making the call.

I guess it gets more complex if you're calling about (say) a rescued windsurfer who is hypothermic.
 
Could say total of three persons and one of those is in the water ? I think that the total number to be rescued is important to get across.

Found this on the RNLI website -
  • The word, 'Mayday' is repeated.
  • The vessel's identity is repeated (include MMSI and International call sign).
  • The vessel's position. This is absolutely vital for the SAR authorities to be able to find the distressed vessel as soon as possible. It can be given in either Latitude and Longitude or as the bearing and distance from a known geographic point.
  • The nature of the distress, such as 'Vessel on fire, sinking, etc.'.
  • Require Immediate Assistance
  • The number of people on board, including the radio operator!
  • Any other Information. This should include any information that might help the SAR authorities locate the vessel and assist in the Distress. Include information such as the vessel's colour, type of craft, the activation of an EPIRB, flares etc.. It is also helpful to give the rate and direction of drift if this is applicable.
 
I've never sent a mayday, but it seems to me that the standard formula gets the information out succinctly and covers most situations. It also, presumably, gives it in the order the coastie needs to enter it into a form.

If your particular emergency doesn't fit, you can add additional information afterwards.
 
I would include the MOB. They want to know numbers onboard so they know how many people/bodies they may have to fish out of the water in the event of a sinking. ie they know when they have found them all and can go home. I guess they also need to ensure they send a boat capable of taking (potentially) everyone from the stricken vessel onboard.
 
CLB said:
I would include the MOB. They want to know numbers onboard so they know how many people/bodies they may have to fish out of the water in the event of a sinking. ie they know when they have found them all and can go home. I guess they also need to ensure they send a boat capable of taking (potentially) everyone from the stricken vessel onboard.
Click to expand...
Yes and in some circumstances, it might be a helo with limited capacity, so giving the total number of people seems sensible to me. But it depends on the circumstances and I think somebody used the words, 'common sense'...
 
Last edited:
capnsensible said:
Writing it next to the radio makes sense along with your radio call sign. It's what the rescuers have asked for to help them help you. ?

In your mayday call it's simple to include the number of people 'remaining on board'.
Click to expand...
Yes, write it next to the radio, it might be the least experienced passenger left aboard making the call!
 
A slight digression: Whatever it says in the RYA/RNLI guidance, I will always be making sure my position, and all the other basics, get sent before reading and reciting strings of bureaucratic numbers and letters.

Time is of the essence. MMSI's and callsigns use time, battery power, crew resources, and are vulnerable to mistakes, especially when rushed/hurt/adrenaline pumping etc.
When a crewmember is holding onto a microphone, trying to read a list of numbers, they can't be doing other, more important things.
I do understand the wish of the CG to confirm the identity of a vessel which has sent a DSC distress.
 
capnsensible said:
Writing it next to the radio makes sense along with your radio call sign. It's what the rescuers have asked for to help them help you. ?

In your mayday call it's simple to include the number of people 'remaining on board'.
Click to expand...
Genuine question, not arguing: Apart from confirming the identity of a DSC distress, how do your MMSI and/or Callsign help rescuers to help you?
 
Gary Fox said:
Genuine question, not arguing: Apart from confirming the identity of a DSC distress, how do your MMSI and/or Callsign help rescuers to help you?
Click to expand...
I suspect that in these days of large Coastguard centres, it means that concurrent incidents can be distinguished readily and unambiguously. MMSI and callsign are (by definition) unique; nothing else in a Mayday call is. It also means that the DSC call initiated automagically by pressing the Big Red Button can be tied in with the voice call without ambiguity; otherwise, they could mistake calls for two incidents for one incident , or even think that there were two incidents where only one was taking place.

From a data management point of view, it makes perfect sense!

The days when a Mayday would be handled by a relatively small, local team are gone, and hence the likelihood of a coastguard office handling several incidents concurrently is increased. The request for the MMSI was instituted at about the same time as centralization was happening.
 
AntarcticPilot said:
I suspect that in these days of large Coastguard centres, it means that concurrent incidents can be distinguished readily and unambiguously. MMSI and callsign are (by definition) unique; nothing else in a Mayday call is. It also means that the DSC call initiated automagically by pressing the Big Red Button can be tied in with the voice call without ambiguity; otherwise, they could mistake calls for two incidents for one incident , or even think that there were two incidents where only one was taking place.

From a data management point of view, it makes perfect sense!

The days when a Mayday would be handled by a relatively small, local team are gone, and hence the likelihood of a coastguard office handling several incidents concurrently is increased. The request for the MMSI was instituted at about the same time as centralization was happening.
Click to expand...
'..Nothing else in a Mayday call is unique..' ....apart from the vessel's name!
I get the centralised data management aspect, things aren't what they used to be in my day, etc etc..
 
You must log in or register to reply here.

Share this page

Top