Mayday - MMSI and Position

[TangaraToo]

Just started studying for SRC and am a little surprised by something.
I don't have the book of words yet (might be explained in that) but I just don't understand why, in an emergency situation you should repeat unique ident and MMSI twice yet only give the position once. I would have thought given the limited time that making sure your position was known was far more important than your MMSI.
Can some kind person explain the logic behind this?
Thanks

 

[telford_mike]

And what if you don't have an MMSI?

Position, problem and number of souls aboard most important.

 

[prv]

Are you sure the MMSI is meant to be given twice? I don't have anything authoritative to hand to check, but I thought it was only once. The idea of that of course is to link the voice call and DSC signal together so they aren't mistaken for two separate incidents.

In practice, in UK coastal waters I would probably just fire off the DSC and then concentrate on dealing with the emergency until the Coastguard call me back. But if taking the time for a voice transmission, I might give the position once as lat and long and again as a verbal description - only the most conscientious small boat users are going to bother plotting an overheard lat and long on the chart to find out whether it's nearby, but "in Christchurch Bay, about two miles west of the Shingles" will catch the attention of anyone in the area.

Regardless of practical considerations like this, the exam calls for word-for-word reproduction of the official format, so for that you'll have to learn whatever's in the official book.

Pete

 

[TangaraToo]

Are you sure the MMSI is meant to be given twice?

Sequence as given in RYA online training course is
Mayday X3
Yacht name x3
Licence Number
MMSI
Mayday
Licence number
MMSI
Position
Problem
Assistance required
Persons on board
Additional info

Would seem far more sensible to me to give position straight after Mayday (x3) as then if radio dies (boat taking on water) at least people will know where you are.
If using DSC then MMSI will already be known from DSC alert. If no DSC then no MMSI.
I am struggling to understand the importance to giving MMSI twice before position is given.

 

[l'escargot]

Your DSC has already given position and MMSI. There is a remote possibility of another unrelated voice distress being received at the same time. I seem to remember it being said somewhere that it is to establish a link between the voice call and the automatic DSC information.

 

[duncan99210]

This is what I was taught and what is up by the radio:

Mayday, Mayday, Mayday
This is ‘YACHT NAME.................’, spoken three times
Mayday – NAME and ‘MMSI* or call sign’, spoken once
My Position is…………….
Nature of Distress………………
Assistance required…………..
Number on board (total crew + skipper)........
Other information
Over

The voice transmission should be made after you've pressed the DSC button to send the digital distress signal. The aim to is fully identify your vessel before going on to talk about where you are and what the problem is.

 

[prv]

Sequence as given in RYA online training course is
Mayday X3
Yacht name x3
Licence Number
MMSI
Mayday
Licence number
MMSI
Position
Problem
Assistance required
Persons on board
Additional info

Would seem far more sensible to me to give position straight after Mayday (x3) as then if radio dies (boat taking on water) at least people will know where you are.
If using DSC then MMSI will already be known from DSC alert. If no DSC then no MMSI.
I am struggling to understand the importance to giving MMSI twice before position is given.

I assume by "License number" you mean callsign? I don't think I've come across the idea of including that before.

Part of the reason for the incongruous structure is that this stuff is laid down by radio geeks rather than sailors. Strictly speaking, the first few lines are not part of the message itself, they're something akin to email message headers -
[table="width: 500"]
[tr]
[td]Mayday, Mayday, Mayday[/td]
[td]- Priority header[/td]
[/tr]
[tr]
[td]Yacht Nonsuch, Yacht Nonsuch, Yacht Nonsuch,
Callsign MSFA5,
MMSI 232123456 [/td]
[td] - Sender ID, in various forms[/td]
[/tr]
[/table]

Then you have the body of the message:
[table="width: 500"]
[tr]
[td="width: 50%"]Mayday Yacht Nonsuch[/td]
[td]- This is a kind of identifier for the incident. You'll hear the Coastguard prefixing all messages to and about Nonsuch with this, including the formal incident-close message once the rescue is complete.[/td]
[/tr]
[tr]
[td]Position, problem, actions being taken, etc [/td]
[td] - The actual useful meat of the message.[/td]
[/tr]
[/table]

It comes from a mindset in which the notional sender of the message has written it down on a printed message pad and handed it in to the wireless room to be transmitted, originally by morse. The "header" stuff is the operator setting up the formal structure of the transmission, then he transmits the body unchanged on the sender's behalf. Once you understand this structure, coming from formal radio service rules, the RYA standard format and what it repeats where seems a bit less arbitrary.

That doesn't mean it's actually sensible outside the ivory towers of the International Telecommunications Union, and in practice it's quite likely to be modified to get the important bits in first and omit the less useful ones.

Pete

 

[[70521]]

in an emergency situation you should repeat unique ident and MMSI twice yet only give the position once.

The preamble is so that brains wake up. Try taking numbers over a poor radio signal, your ears need to be in full operational mode.

Making sure you have the correct MMSI number means you can match that to the electonic distress message.

Speaking to Coast Guards on both sides of the Channel even if you don't do a proper message they will respond, BUT doing it correctly really helps them as the format is international.

 

[duncan99210]

It's important to bear in mind that the format is not one put together by the RYA but an internationally recognised format. Any coastguard station is going to be listening for the various elements of the message in the correct(ish) order, so that they can focus their often limited English speaking skills on the important bits rather than on trying to decipher a panicked message delivered in wrong order.
The format also helps you sort out the information required in your head before you start talking. It may not be the best way of doing it but everyone who hears the initial call will have a few moments to gather their thoughts and get hold of a bit of paper to write down the important bits.

 

[Sybarite]

Sequence as given in RYA online training course is
Mayday X3
Yacht name x3
Licence Number
MMSI
Mayday
Licence number


MMSI
Position
Problem
Assistance required
Persons on board
Additional info

Would seem far more sensible to me to give position straight after Mayday (x3) as then if radio dies (boat taking on water) at least people will know where you are.
If using DSC then MMSI will already be known from DSC alert. If no DSC then no MMSI.
I am struggling to understand the importance to giving MMSI twice before position is given.

I have an instance where this sequence was really a problem. A sailor had taken to his liferaft in a real emergency situation and all he had to communicate with was his cell phone which indicated that he was out of range. He got through anyway and his correspondant started going through the list. He had to shout to get her to note in priority his position before he would lose contact. Without that, all the other questions were meaningless.

Because of an explosion on board, his VHF was inaccessible.

OTOH some of the information that the Coast Guard wants is to ensure that it is not a hoax call.

 

[jerrytug]

So saying the radio callsign is to allow time for hearers to find a pencil, and saying the MMSI is to allow time for finding a piece of paper.
Did Tony Hancock have any input on this surreal proceedure by any chance?

 

[NormanS]

I could just see me in an emergency situation, worrying about a "Licence Number". Must say, I've never heard of that nonsence before.

 

[prv]

I could just see me in an emergency situation, worrying about a "Licence Number". Must say, I've never heard of that nonsence before.

I think by "Licence number" he means the callsign.

I have a smart little engraved placard next to the radio with the boat's name, MMSI, callsign, and SSR number. I don't intend to read all of those out in a Mayday call though - maybe the MMSI at best if there's not too much of a rush.

Pete

 

[Rivers & creeks]

This is what I was taught and what is up by the radio:

Mayday, Mayday, Mayday
This is ‘YACHT NAME.................’, spoken three times
Mayday – NAME and ‘MMSI* or call sign’, spoken once
My Position is…………….
Close to feature x or "" miles from feature x
Nature of Distress………………
Assistance required…………..
Number on board (total crew + skipper)........
Other information
Over

The voice transmission should be made after you've pressed the DSC button to send the digital distress signal. The aim to is fully identify your vessel before going on to talk about where you are and what the problem is.

I agree but I've added a line we have as well as what's above.

 

[capnsensible]

Quite simply, a few years ago at an international radio conference, the latest Mayday procedure was discussed and agreed.

This was at the request of the people, worldwide, who are going to answer Your Distress Call.

Think of it as them actually knowing what they are doing and how best they can help you.

It also helps if one actually switches the radio on, an old chesnut on here.......

Google will, I am sure, reveal the precise authority by which this decision was made for those that need more information.

CS

 

[johnalison]

I have a smart little engraved placard next to the radio with the boat's name, MMSI, callsign, and SSR number. I don't intend to read all of those out in a Mayday call though - maybe the MMSI at best if there's not too much of a rush.

Pete

I have a smart little laminated instruction sheet. On one side is the panic Mayday routine and on the other side the procedure for a DSC Mayday call.

 

[JumbleDuck]

So saying the radio callsign is to allow time for hearers to find a pencil, and saying the MMSI is to allow time for finding a piece of paper.
Did Tony Hancock have any input on this surreal proceedure by any chance?

Is it official or (yet another) RYA invention?

 

[capnsensible]

Is it official or (yet another) RYA invention?

Why would it be an RYA invention?

The directives are merely implemented into RYA training so everyone has the option to understand it.

Here are the geezers you may wish to send your opinion to:

http://www.itu.int/ITU-R/index.asp?category=conferences&rlink=wrc&lang=en

Enjoy.

 

[Bluebird]

The OP is correct. The MMSI and Call Sign are now meant to be repeated as specified by the ITU. First time in the distress alert, second time in the distress message. I can only presume this is to ensure that the caller has said it correctly and the listener has copied it down correctly.

In reality, the CG will be pleased to hear it said at all. And yes, it is to confirm that the DSC message received is the same as the voice message received.
The change was announced in 2011 and it was discussed on this forum - http://www.ybw.com/forums/showthread.php?272589-New-VHF-Mayday-Distress-Procedure

 

[l'escargot]

I was taught that if hou have sent a DSC distress, and you follow that with a voice distress, then you MUST include your MMSI so they can tie the two messages together and know they are dealing with ONE emergency.

Failure to include your MMSI in the voice message, and they won't be able to tie the two together and they must assume there are TWO current emergencies.

...and it is only logical to include the name of the vessel and the MMSI number so the coastguard can relate your call to the received dsc alarm!...

...When you issue the verbal distress call after the DSC call you need to include the MMSI so that any DSC equipped boat knows that the verbal call is from the same boat that sent a dsc call and not a second emergency...

...I agree with ProDave that the MMSI seems important to let the CG match the voice and DSC messages together...

Your DSC has already given position and MMSI. There is a remote possibility of another unrelated voice distress being received at the same time. I seem to remember it being said somewhere that it is to establish a link between the voice call and the automatic DSC information.

...Making sure you have the correct MMSI number means you can match that to the electronic distress message...

...And yes, it is to confirm that the DSC message received is the same as the voice message received...

I think I can see a common theme here...