DSC Alerts - A voice speaks in the wilderness...

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Woodentop

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You said;
>I am somewhat bemused that DSC usage is not always two-way. I boat out of Weymouth and, of course, Joburg Traffic is a constant annoyance to us in the area (and others no doubt?)

I agree.

You said;
>If AIS is in use, as it is supposed to be, then why does the coast station call up a vessel using it's position, speed and course (taken from the radar I expect) instead of using the MMSI direct to the vessel ?

Is AIS in use ? Oooh Lordy ! We have had AIS in Portland MRCC for over a year. This was a trial of the system. The trial has proved a success so the system has been removed. The final version will now be installed sometime next year. This is to meet our requirement for UK Maritime Vessel Reporting by 2004. (Blame Prescott - you voted for him, I only work for him).

A coast station with AIS should be able to give the ship a DSC "ping" and call them direct (not using 16). Unfortunatley the French (Jobourg in particular) don't have the gear.

You said;

>We recently had Solent CG calling a boat by name and also MMSI - if they knew the MMSI why wasn't it used ? If it was and wasn't answered then why try in plain voice ?

Because the boat did not respond to to the return DSC ping. Let me explain - The MRCC recieves a DSC ping. We reply with another DSC ping which automatically re-tunes their radio to the channel we choose (usually 67) then we say "Station calling Toytown Coastguard, this isToytown Coastguard...etc..."

Often the user of the radio who called us by DSC does not realise that the replying station has re-tuned their radio, i.e.switched it to a different channel without their knowing it. And thus the confusion begins.


Let us get one thing clear......

If you "ping" another staion ( yacht or Coastguard or Oil Rig or something else) by DSC they will reply by DSC "ping" and that "ping" will switch your radio to a different channel... the one they want to talk to you on.
If you then change channel (knowingly or unknowingly) all is chaos.

The station you pinged knows your MMSI number but does not know your boat name... unless they do a quick run through Gooogle to the ITU database in switzerland to match the MMSI to a boat name.


Now to the practicalities: You pop out of Weymouth to Cherbourg and wish to tell the CG that you are going so that if you fail to arrive someone will notice.

Option 1 goes like this;
(Ch 16 Voice)- "Portland Coastguard this is Black Pig etc...."
"Black Pig go to Ch 73 for routine traffic etc....."

(Ch73 Voice)" Black Pig this Portland etc...." and the details are passed

Option 2
(Ch 70 - electronic) "Ping to Portland"
(Ch 70 - electronic) "Ping back" which retunes your radio to Ch 73 and we say " Station calling Portland.. What do you want ? etc...."

Sadly when you "ping" us your MMSI we see it as 232123456 and we cannot translate this number into "The good ship Black Pig" in less than a couple of minutes so it is quicker for us to say "Station Calling us, Who are you and what do you want ?..."

You said;
>I'm missing something, but still.."

My perception is that for routine stuff simple voice is quicker than hi-tech labour saving devices.

When the pooh hits the fan and you stay afloat for 5 seconds more, long enough to hold down the red buttonnb then VHF DSC is useful.


Did I answer your question ?
 
Well done Woodentop. I haven't read the questions yet, but what you have written here explains a lot. With your permission I would like to use parts of it for training purposes. I will pm you.
 
I still think it would have made a lot of sense to have the callsign incorporated into the MMSI number. Much easier to remember a few letters and a number or two than a string of nine numbers, and easily recognised over the radio.

ie.... my callsign is MNWJ4, whereas my MMSI number is 235027246. Given that the first 4 numbers are a "identifyer" for the station, for me, 2350MNWJ4 would be sooooooooooo easy to pick out of the airwaves!

Spilt milk and all that.........
 
At last the voice of reason!

Thank you for that information, it confirms many if not all of my own thoughts and some of the 'questions' you answered were even mine! It is nice also that at last we have confirmation that there IS actually a problem and one which is perhaps more apparent in our (Central Channel) area, because good folks from the East Coast, Wales and Scotland and even the Solent and South East have doubted us in the past.

As you say, simple voice is just that - simple quick and effective as it always was and the little red button can be reserved for the day you hope that never comes. Now if we could just persuade Joburg and the RN to be a little less free with the repetition of the same alerts at 20min intervals and get rid of the Radiocheck Junkies we might be able to leave the set on all the time..

Robin
 
Minor correction - when the CG sends a responding 'ping', the channel on my set doesn't change until I have pressed a button to accept the call. I don't know how universal that is.
 
[ QUOTE ]

You said;
>If AIS is in use, as it is supposed to be, then why does the coast station call up a vessel using it's position, speed and course (taken from the radar I expect) instead of using the MMSI direct to the vessel ?

Is AIS in use ? Oooh Lordy ! We have had AIS in Portland MRCC for over a year. This was a trial of the system. The trial has proved a success so the system has been removed. The final version will now be installed sometime next year. This is to meet our requirement for UK Maritime Vessel Reporting by 2004. (Blame Prescott - you voted for him, I only work for him).

A coast station with AIS should be able to give the ship a DSC "ping" and call them direct (not using 16). Unfortunatley the French (Jobourg in particular) don't have the gear.


[/ QUOTE ]

Finally AIS would make DSC useful at last. We have the idea of integrating a software interface from our AIS software to the DSC set. This would enable the user to directly "ping" any vessel/coaststation fitted with AIS and, by way of returned "ping" with information about the working channel, to establish voice communications directly. And with the upcomming AIS Class B quite a lot of recreational boats would be fitted with AIS...

The only problem is that the manufacturers of DSC sets are not willing to reveal the data sentences used by their DSC sets....

Holger
 
Morning Woodentop,

Do you mind me getting my oar in here? Have to agree with you about the difference between routine and distress use of DSC.

The DSC calling for routine traffic is a bit unnecessary for calling us at Solent, as we keep a listening watch on Ch67 as well as Ch16. It is so much easier for us when someone calls us direct on Ch67 to pass routine traffic than to call us up on DSC or CH16. If for some reason a routine RT call goes unanswered, then a Ch16 call or DSC hit would be the next step. (This may well differ in more remote areas, but is good for us.)

Where a DSC hit from a pleasure vessel is really good is when the proverbial is on the fan, then the distress alert is a brilliant feature. Position, Identity, lovely.

However, one interesting incident, we took a distress hit from a boat that had struck the Varvassi wreck on the Needles, there was no subsequent RT comm.s and the DSC radio was newly registered so we could not decode the identity. We called the MMSI of the distressed boat - 5 other yachts told us that we should stand down the distress as it was their DSC units malfunctioning. They were reading the DSC number from the display of their radio's which were correctly showing the distressed vessel's MMSI - and they thought it was their own MMSI. Good job we didn’t believe them all, but this certainly got in the way - finally the skipper of the distressed boat came up on Ch16 and we sorted his problem out. (He had been a bit busy after hitting the distress button.)

If everyone used the office dymo machine to print off their callsign and MMSI, and stuck it next to the radio, it would be good. Really good.

I’m looking forward to our new AIS software coming, it turned out to be useful for SAR over the summer, and I hear the new DSC software should interface with this when it comes in a couple of years and have a built in database link to decode the MMSIs. When that happens, perhaps DSC for routine traffic may be more relevant for us?
 
one hopes HMCG have something better than ITU to match MMSI to ship's name with. It's hopelessly out of date. Lloyds Fairplay database (ISR) is infinitely better, imho, although it's not free ..
 
Can't you get an AIS data link from "The Grove" (MMSI 002320722) Base Station which looks to be just up the road from you? Surely it receives as well as transmitting?
 
On the subject of 'Routine Traffic' - what is the benefit to yachts, the CG or, indeed, anyone, in making a routine traffic report?
 
Woodentop

"Now to the practicalities: You pop out of Weymouth to Cherbourg and wish to tell the CG that you are going so that if you fail to arrive someone will notice."

Do Weymouth CG contact Cherbourg CG to let them know your plan so that Cherbourg will know when you are late?
 
Thank you Woodentop, as most of those questions/comments were posted by me I believe it is good to get such a succinct answer.

As you are no doubt aware it is Oh So easy for us who know little to raise comments about others who are out of our reach (physically anyway). I must admit that I thought that HMCG had a database linking the MMSI with ships names, the fact that you haven't makes the reason for the current actions quite obvious.

As stated, a cheapskate Government never helps anybody.

Once again, thanks for the response.
Sandpiper out.
 
[ QUOTE ]
one hopes HMCG have something better than ITU to match MMSI to ship's name with. It's hopelessly out of date. Lloyds Fairplay database (ISR) is infinitely better, imho, although it's not free ..

[/ QUOTE ]

Yes, we have our own database, data supplied by OFFCOM for SAR purposes. This does not include any non UK registered vessels but is pretty much live for UK vessels.

You are quite right, we buy Fairplay which is expensive, and so one station has access and can be requested to interrogate should we need to. We also buy Lloyds list and weekly movements and so on.

The ITU web access is the international database, and is free, quick and easily accessible. There is a short delay in the transfer of data to the ITU from member countries registration authorities being entered into their database, but it seems to be no more than 2-3 weeks later than our UK database for UK vessels in my experience.

Hope that helps.
 
[ QUOTE ]
Option 2
(Ch 70 - electronic) "Ping to Portland"
(Ch 70 - electronic) "Ping back" which retunes your radio to Ch 73 and we say " Station calling Portland.. What do you want ? etc...."


[/ QUOTE ] Maybe the response should be "Station Pinging Portland.. etc" /forums/images/graemlins/wink.gif
 
[ QUOTE ]
On the subject of 'Routine Traffic' - what is the benefit to yachts, the CG or, indeed, anyone, in making a routine traffic report?

[/ QUOTE ]

Hi,

Well, your passage plan will have identified the need to lodge the plan with someone ashore should things go "wrong".

So you leave details with your shore contact, including number of folks on board, where and when you’re going from, where and when you plan to arrive, likely alternative ports of call and so on.

Now if you have called us as you leave your port of departure, you have confirmed the correct information to us - the real story of who is on board and so on, (just in case aunt Ethel changed her mind and decided not to go after all or you missed the tide and got delayed or whatever).

Later, when you don't call the shore contact upon safe arrival, they tend to get a bit worried, and after a while they call us and report you as overdue – which is where we start getting interested. First thing is to look in our log for your Traffic Report (TR), as the info from you may be different to what the shore contact has. It really happens quite a lot that the shore contact has not got the latest info and that the vessel has been delayed by weather or whatever, so then makes sense just to call you up and make sure you are still OK and we can reassure those shoreside.

If the TR shows that you are indeed overdue, then we have confirmation that you did leave etc and we should have the outline of a passage plan, which makes looking for you so much easier. So we call you on VHF and mobile phones, make broadcasts in case any one else has seen you, get the points of departure and arrival checked, and then those likely alternative ports and so on and so on. If the weather or some other factor indicates some urgency / distress then we can step up the anti to a full blown search

Not all shore contacts are familiar with nautical stuff so the information we can receive can be very scarce, can have the wrong ports, wrong boat name, wrong ETD/ETA, wrong number of persons on board, you name it. Descriptions of the boat can be as good as “white, it must be big as it is so expensive” to “it has sails”. Honest. ( you ask your parents / wife / daughter in law / someone to describe your boat to you.) The CG66 database really does work.

So with a TR we get the real story, and know we have spoken with you, and so if everything is well onboard, we should be able to talk with you again to confirm that if reported overdue. It is important to note that unless you specifically ask us to make regular safety checks with you because something has gone awry with the plan or the boat, then it is up to the shore contact to tell us you are overdue, it is not for us to follow up every TR we get for safe arrival.

A TR should fall from your passage plan. Do you need to make one? Is this a trip that you make every weekend - with very little risk as it is a lovely sunny calm day on neaps, or is it the same trip but blowing dogs off chains on spring tides? Personally, if it is a trip that includes some reasonably high amount of risk then I make a TR.

Hope that helps.

(By the way – just in case anyone has the thought - I’m not writing this on Watch wasting tax payers money, I’m a sad Muppet at home who can’t get down to the boat)
 
[ QUOTE ]


Hope that helps.

(By the way – just in case anyone has the thought - I’m not writing this on Watch wasting tax payers money, I’m a sad Muppet at home who can’t get down to the boat)

[/ QUOTE ]

It certainly does help. If you were writing this on Watch, I for one would not think of it as wasting tax payers money. More like making good use of the time, and educating the great unwashed boating public! A stitch in time saves nine.
 
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