Vhf call sign and MMSI

[OceanSprint]

I know that you put the vhf call sign in a mayday, but when else do you use it? I can't see it anywhere else in the Rya book ( and yes, I have done the course and got my short course licence ).

Also

The MMSI number is a right mouthful in a mayday situation. Vhf call sign is a unique identifier. And I' m sure the mca have a very efficient database that links the two - so would you really read out the MMSI number in a mayday if you have already given the call sign and boat name?

 

[mikemanor]

If you call the coastguard or a harbour authority and have a common boat name you may be asked for your callsign which identifies you on the list on their database which comes up when they put in your boat name.

The MMSI number is what appears on the coastguard's screen when you "press the red button" so it is given in the distress call and message to positively link the voice call to the distress alert. There have, apparenty, been instances where the wrong MMSI has been programmed into the ship's set leading to confusion hence both callsign and MMSI are given. Remember this is a UN procedure not an MCA procedure.

What you do of course.....

 

[ProDave]

I was taught to put the callsign AND the MMSI in a mayday.

If you have pressed the SDC distress button first, it ties your verbal mayday to the DSC one, so they know it's just one incident.

 

[OceanSprint]

I was taught to put the callsign AND the MMSI in a mayday.

If you have pressed the SDC distress button first, it ties your verbal mayday to the DSC one, so they know it's just one incident.

I realise that, but don' t you think with the wonders of microsoft, MMSI number, vhf call sign, boat name and ssr registration will all pop up on the coastguard computer screen when any two of above entered into "search" ?

 

[OceanSprint]

If you call the coastguard or a harbour authority and have a common boat name you may be asked for your callsign which identifies you on the list on their database which comes up when they put in your boat name.

The MMSI number is what appears on the coastguard's screen when you "press the red button" so it is given in the distress call and message to positively link the voice call to the distress alert. There have, apparenty, been instances where the wrong MMSI has been programmed into the ship's set leading to confusion hence both callsign and MMSI are given. Remember this is a UN procedure not an MCA procedure.

What you do of course.....

Ok, I can buy that. But when else is the vhf call sign used? We are not ham radio- ers?

 

[Bilgediver]

I realise that, but don' t you think with the wonders of microsoft, MMSI number, vhf call sign, boat name and ssr registration will all pop up on the coastguard computer screen when any two of above entered into "search" ?

In an ideal world maybe! However with so many VHF sets floating in and out of jumbly sales and the chance of some not being on the boat they are supposed to be on then it is quite reasonable to start the VHF Mayday using call sign and MMsi and even the boat name too so that the uncertainty is removed.

 

[prv]

Ok, I can buy that. But when else is the vhf call sign used? We are not ham radio- ers?

No, but we are licensed radio stations, and therefore under international telecommunications law we have to have call signs. You're correct to observe that they're rarely used on yachts.

Pete

 

[OceanSprint]

No, but we are licensed radio stations, and therefore under international telecommunications law we have to have call signs. You're correct to observe that they're rarely used on yachts.

Pete

So is the call sign not used for anything other than maydays? And possibly forum messages signatures?

 

[Beadle]

I was taught to put the callsign AND the MMSI in a mayday.

If you have pressed the SDC distress button first, it ties your verbal mayday to the DSC one, so they know it's just one incident.

I can't think who taught you that.

Can anyone believe that in a life threatening emergency anyone is going to accurately read out a 97 digit number.

Does anyone think it matters to the coastguard receiving the call - what he wants is your position - given that he can get help to you. Anything else will help, but position is the main thing.

Its unlikely that there will be more than one boat in distress in the same place - even if there is, the lifeboat or whatever other resource he sends will not ignore one because he didn't make a Mayday call in a particular format.

These are real practical people who understand the stress of an emergency and are too highly motivated to let non adherence to a specific formula get in their way.

 

[l'escargot]

I can't think who taught you that...

Any qualified instructor. The correct procedure now is to give your call sign, MMSI number and position in a voice message after the DSC alert, as well as other information such as nature of emergency, action being taken, people on board etc. The coastguard will still react on the DSC alone though.

 

[Pye_End]

I realise that, but don' t you think with the wonders of microsoft, MMSI number, vhf call sign, boat name and ssr registration will all pop up on the coastguard computer screen when any two of above entered into "search" ?

A Mayday is not just for Coastguard to hear.

The MMSI is useful for all to tie in the DSC broadcast with the spoken Mayday message so that all know what they are dealing with one incident and not two.

If you fail to use correct procedure because there isn't time, it is unlikely anybody will be too critical.

 

[mcframe]

The MMSI number is a right mouthful in a mayday situation. Vhf call sign is a unique identifier. And I' m sure the mca have a very efficient database that links the two - so would you really read out the MMSI number in a mayday if you have already given the call sign and boat name?

When I've done DSC test calls to CG, they have been happy with aviation-style "MMSI ending XXXX"

Planes do full call sign on initial call, then drop to last two letters for subsequent comms.

 

[rivonia]

Another advantage of giving out your call sign AND mmsi number is for relay purposes any one within range can then pass on the full report.

 

[Bosun Higgs]

I realise that, but don' t you think with the wonders of microsoft, MMSI number, vhf call sign, boat name and ssr registration will all pop up on the coastguard computer screen when any two of above entered into "search" ?

This is government IT we are talking. Its some time since I last vbisited a coastguard station but at that time the MMSI etc were all on a seperate PC in the corner and not on the screen as you put it

 

[KellysEye]

The only time I was asked for our call sign was when I did an SSB radio check with Thames Coastguard, otherwise the boat's name has been fine. On the other hand we did see a boat called 'Exocet Attack' which Falmouth Coastguard might take seriously.

We had MMSI but never used it.

 

[Beadle]

Another advantage of giving out your call sign AND mmsi number is for relay purposes any one within range can then pass on the full report.

Do you mean like calling "Mayday relay - mayday relay"?

By the time you recited the MMSI twice (if you can remember it) the poor burger would have sunk.

Nonsense is nonsense no matter who teaches it.


A further point is that if the coastguard can hear you saying the number he must also be able to receive your MMSI signal giving your number electronically so where is the added value?

If he can't hear your voice signal he might be able to receive your MMSI signal and know the number and whatever you say is irrelevant

If he can't hear either you or your MMSI you are are down to another vessel hearing one or the other - and I cannot see what value your telling the other vessel your MMSI number may be - announcing your position would be more use.

BTB I've just been over the guidelines on the RYA site - no mention there of reciting the MMSI number

 

[jerrytug]

When I inform Dover CG I'm going to France (boat on CG66) I always just give the name and callsign and they never ask for the MMSI. I know both off by heart anyway,but there is no way I would be giving out my MMSI if I was rapidly sinking.
If not about to sink (or burn god forbid) then ok,but as Beadle says, how could either other vessels,OR Cg,confuse two maydays from the same point and time,DSC or not?
Someone needs to explain what advantage it could have speaking nine numbers slowly and clearly after one has just hit a box awash or whatever,anyone on a bridge for example would already be getting both anyway!All the best Jerry.

 

[winsbury]

I believe one of the reasons to state mmsi other than for id purposes is to slow the message tranmission ( which may well be spoken faster than ideal when in difficulty ) sufficiently that listeners can grab a pencil to record the mayday message in particular lat long which is also why position is later on in the message and can then respond if necessary...not all maydays are in the vicinity of a coastguard! Practise writing a mayday down and bear in mind a pad and pen might not be immediately to hand and I think its easier then to appreciate the difficulty from the receivers point of view and why the procedure seems so verbose.

 

[jerrytug]

I believe one of the reasons to state mmsi other than for id purposes is to slow the message tranmission ( which may well be spoken faster than ideal when in difficulty ) sufficiently that listeners can grab a pencil to record the mayday message in particular lat long which is also why position is later on in the message and can then respond if necessary...not all maydays are in the vicinity of a coastguard! Practise writing a mayday down and bear in mind a pad and pen might not be immediately to hand and I think its easier then to appreciate the difficulty from the receivers point of view and why the procedure seems so verbose.

Winsbury you make an extremely good point about being quick and accurate jotting down coordinates! I practise on VHF11,the Dover Strait news and info,tugs with half mile long tows eg are nice to know. They give approx position,could be coordinates or from (eg Sandettie Lanby) true degrees plus distance,then approx course and speed.
People should never be shy of getting out the pencil and going straight to the chart with such infos.
Situational awareness to me is everything.
How does it relate to MMSI please explain,cheers Jerry
Actually I think you might be making a point,is the taught proceedure of saying MMSI slowly to give other stations time to get a pencil !!?? ha ha!

 

[winsbury]

Actually I think you might be making a point,is the taught proceedure of saying MMSI slowly to give other stations time to get a pencil !!?? ha ha!

Im pretty sure thats what the instructor that we had implied.