DSC procedure

MarkJohnson12345

MarkJohnson12345

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Swansea Wales UK
www.markjohnsonafloat.org.uk
On my recent cruising holiday, I called the coast guard three times in four days using DSC to report my passage plan.

Each time I had a different response.

The procedure is to call the MMSI number of the coast guard, and wait for the response. I then acknowledge the response by pressing the 'Enter' button.

So far so good

The first time, having pressed the enter button I waited for the CG to call me me. Nothing happened for several minutes. So I did a verbal call on Ch16 then reported the passage plan on Ch67, and asked why the unexpected response to the DSC call. The GG said that they were waiting for me to call them.

The second time I called, once I had acknowledged their DSC response, I immediatley verbally called them on Ch67. I then found that they were talking to someone else! I waited for that conversation to end, and repeated my call to them saying that I was the DSC caller. I reported my passage plan with no problems.

The third time (2 days later) having gone through the initial procedure, and I had acknowledged their DSC reponse, the CG reponded so quickly to the 'DSC caller', and the passage plan was reported succesfully.

I have a certificate for use of the DSC radio, a course done about two years ago.

My point is that I am not sure what is the correct procedure when calling the coast guard. When calling verbally, we always wait for him to come back on Ch67 before carrying a passage plan report or whatever.

Not sure that the coast guard was sure either!

I assumed that their computer system would instantly recognise my MMSI number and they would e able to respond to 'Triton'. But I suspect that the coast guard has no idea who is calling them, just a number on their radio/computer system. Thus it must be a little difficult for them to return the call when busy. My Swansea Coast guard returns my call by saying 'Boat calling with MMSI number ********' a little complicated if you ask me, especially as I don't readily recognise my own MMSI number.

great system, but it does not yet seem to be implemented properly.

But what government agency has yet succesfully spent their millions on working computer system??????
 
Haven't had to use the system yet, I too am certificated(recent upgrade from VHF).

Your first experience would have thrown me, the second an irritation. I naively would have expected the third response only.

Forewarned is forearmed though- thanks
 
[ QUOTE ]

I assumed that their computer system would instantly recognise my MMSI number and they would e able to respond to 'Triton'. But I suspect that the coast guard has no idea who is calling them, just a number on their radio/computer system. Thus it must be a little difficult for them to return the call when busy. My Swansea Coast guard returns my call by saying 'Boat calling with MMSI number ********' a little complicated if you ask me, especially as I don't readily recognise my own MMSI number.

great system, but it does not yet seem to be implemented properly.

But what government agency has yet succesfully spent their millions on working computer system??????

[/ QUOTE ]

The MCA do not have a database of all MMSI numbers that "instantly" identify you. They will, in the main, use the MARS database to get your details. Have you registered your CG66? This is also supposed to link but recent enquires have shown that not to be the case.

There does not seem to be a standard response to DSC "routine" alerts at the moment. I would tend towards making a voice call directly on Ch67 which is the small ships safety channel and speak direct. As with any routine call, it is only the MMSI number that appears on the receiving screens set. As to you not recognising your own MMSI number, may I suggest you have a procedure card by the VF so you can not only recognise it, but in the vent of making a Mayday or a PAN PAN, you have it readily to hand.
 
I believe it's supposed to work like this:
1/ Select the recipient's MMSI from the directory or enter it manually.
2/ Check the working channel you want to use is clear of traffic and select it.
3/ Place the call (on 70)
4/ When you get the 'ack' alarm press your PTT button and you start the conversation with your MMSI and callsign or boat name... (The set switches automatically to the selected channel and the PTT button cancels the 'ack' alarm.)

This procedure seems to work OK for me.
 
Why use DSC to call the coastguard at all? It's intended to reduce the calling traffic on channel 16, but it seems much easier to simply call them directly on 67.

As others have said, DSC just does the initial calling and allows the receiver to select a working channel. When you press 'ack' your set should tune to that working channel, but you still have to make the initial contact on the working channel.
 
YEs off course my CG66 is registered complete with MMSI number, and I could and should have it written down in my log book.

But the point is that from three calls, there were three different reponses.

I am still reluctantant to charge in in with voice return call on channel 67, as the second experience proved. But maybe that is the logical solution as the CG presumably will only ring you when he is ready.

As said one of the DSC aims is to reduce channel 16 traffic. Other most important of course is to provide standardised Emergency calls along with a lat and long.

I do think its a good system, just everyone needs to know how to use it.

Me included!!!!
 
In the case of the coastguard, you can nominate whatever working channel you want but they will change it to the one they want to use. Then you listen into that channel (you cant really do so beforehand because they are now using lots of channels other than 67) and if it is clear, call them.

When I visited Swansea CG, your DSC details were on a seperate stand alone computer system that required the operator to get up out of his seat, walk ove, find and wirte the details, then return to his seat. Not surprisingly, they didnt do that as routine and therefore cannot call you back by name when they only have your MMSI.

And it makes sense to use DSC to call them because it frees up 16
 
If you want to do a really bad thing to your chums, give them a friendly ship-to-ship DSC call. If they don't respond, you can call them another two or three times to see if they've found the manual. My, how we laughed....

It is a system with very few "intuitive" aspects about it IMHO.
 
Hm, you have met with inconsistencies. We have DSC'd Falmouth 2x, Dublin 2x, Liverpool 2x, Belfast 5x and Clyde 2x - same procedure with them all: once they acknowldege we initiate voice contact. Worked OK.

Suggest you take it up with whichever CG you have had the inconsistent experience.
 
Oh dear MArk.....did your instructor forget to tell you that you chould have your MMSI number displayed along with your call sign adjacent to the radio !!!!!! /forums/images/graemlins/smile.gif

John
 
[ QUOTE ]
The procedure is to call the MMSI number of the coast guard, and wait for the response. I then acknowledge the response by pressing the 'Enter' button.

So far so good

The first time, having pressed the enter button I waited for the CG to call me me. Nothing happened for several minutes. So I did a verbal call on Ch16 then reported the passage plan on Ch67, and asked why the unexpected response to the DSC call. The GG said that they were waiting for me to call them.


[/ QUOTE ]

From memory, I think you initiate the DSC, then they reply via DSC and your VHF changes channel to their chosen channel. It is then up to you to initiate the first verbal communication on the selected channel.... which seems to make sense as they were waiting for your call.

Cheers
 
[ QUOTE ]
In the case of the coastguard, you can nominate whatever working channel you want but they will change it to the one they want to use.

[/ QUOTE ]

You can not nominate the working channel when calling a shore station. Is this what you are saying, i.e. it does not matter which channel you have selected when you make the DSC call the shore station will control the channel when they accept?

Just trying to make it clear to those who have not done the RYA ltd. upgrade, or to me who thought as I wrote above.
 
[ QUOTE ]
Why use DSC to call the coastguard at all? It's intended to reduce the calling traffic on channel 16, but it seems much easier to simply call them directly on 67.

[/ QUOTE ]

Be careful!

Try this outside Lake Solent and you will get your ear wrapped for calling on the working channel. Always clarify with, Solent ask you to call on 67.

In the Oirish Sea, they certainly do not want to be called on the working channels.

Not a flame, just clearing something up, hopefully.
 
[ QUOTE ]
You can not nominate the working channel when calling a shore station.

[/ QUOTE ]Well, actually you have to nominate a channel. Your DSC radio only knows that you are making an 'individual' call and requires you to nominate a channel. It's just that the shore station's acknowledgement contains a working channel number that overrides your selection. I know that's pretty much what you said but from an operational point of view there's really no difference between calling another ship station and calling a shore station. Why worry what channel is selected? If it's clear just start your call identifying yourself with your MMSI and boat name.
 
[ QUOTE ]
We have DSC'd Falmouth 2x, Dublin 2x, Liverpool 2x, Belfast 5x and Clyde 2x

[/ QUOTE ]

Why do people talk to the coastguard so often? Just interested.
 
Hi Mark...had the same confusion as you last year. Wait for the aknowledgement and then initate the call on 67 (or whatever working channel they use) seems to be correct. But...at one of the boat shows I asked at the CG stand to confirm this. They weren't entirely sure either and said "we're just learning all this as well"! At one point last year they were asking people who called on 16 if they had a DSC set, and if so to use a DSC call. I haven't heard this for a long time; most people at my end of the Bristol Channel still seem to call on 16. CG seems happy with it...but we don't have the traffic here like on the S.Coast.
 
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