Anyone experienced this? False DSC PAN PAN

davierobb

Active member
Joined
17 Sep 2005
Messages
414
Location
Prestwick, Scotland
www.guesthouseprestwickayr.co.uk
We were anchored off Bute (Clyde) today and we had two or three boats call us up to offer assistance as apparently the had received a DSC PAN PAN from us. The pan pan appeared to have our correct position. We hadn't sent a pan pan and nobody was near the vhf, also our raymarine plotter isn't integrated with the Saillor DSC VHF. Additionally there was no indication on any pan pan being sent in the sailor logs.

We called up Belfast coastguard and they had no record of our pan pan. Our vhf installation is above first class and our range is at or above the theoretical max range. We were probably within 5 miles of the coastguard mast so I can't see how Clyde boats could receive a pan pan from us that wasn't recieved by the coastguard.

One guy contacted us after he heard it was a false alert, we had a useful discussion and he told me his log also had the pan pan but only the first 7 digits of the normal nine digit mmsi number.

The coastguard did say they had had other issues with pan pans earlier and thought it was due to corrupted messages somehow being transmitted and recieved. I can't understand how a corrupted pan pan, that we never sent, could somehow have our correct lat/Long position. The did say that the pan pan might have originally come from a commercial ship somewhere down south ànd possibly it had been retransmitted by them.

Very confused and interested others thoughts.
 

Plum

Well-known member
Joined
6 Jun 2001
Messages
4,387
Location
UK East Coast
Visit site
We were anchored off Bute (Clyde) today and we had two or three boats call us up to offer assistance as apparently the had received a DSC PAN PAN from us. The pan pan appeared to have our correct position. We hadn't sent a pan pan and nobody was near the vhf, also our raymarine plotter isn't integrated with the Saillor DSC VHF. Additionally there was no indication on any pan pan being sent in the sailor logs.

We called up Belfast coastguard and they had no record of our pan pan. Our vhf installation is above first class and our range is at or above the theoretical max range. We were probably within 5 miles of the coastguard mast so I can't see how Clyde boats could receive a pan pan from us that wasn't recieved by the coastguard.

One guy contacted us after he heard it was a false alert, we had a useful discussion and he told me his log also had the pan pan but only the first 7 digits of the normal nine digit mmsi number.

The coastguard did say they had had other issues with pan pans earlier and thought it was due to corrupted messages somehow being transmitted and recieved. I can't understand how a corrupted pan pan, that we never sent, could somehow have our correct lat/Long position. The did say that the pan pan might have originally come from a commercial ship somewhere down south ànd possibly it had been retransmitted by them.

Very confused and interested others thoughts.
There was a case on the East Coast last year of a hh dsc vhf that automatically sent a dsc distress. The CG did receive it and acted. Turned out to be a faulty hh VHF that was only a few months old..
 

jlavery

Well-known member
Joined
25 Oct 2020
Messages
592
Visit site
Can a DSC radio transmit a coded PAN PAN? I thought they only did MAYDAY messages. Haven't seen the option on mine. Unless it's an option once the Big Button has been pressed.
 

jlavery

Well-known member
Joined
25 Oct 2020
Messages
592
Visit site
yes - although just as MAYDAY is call DISTRESS in dsc world, PANPAN is called URGENCY.
Ah, so it is! But on my Icom you have to go through several menu items ("All Ships" call, then select "Urgency" category).

So I suppose a faulty unit could end up transmitting an Urgency/PANPAN call.
 

bergie

Member
Joined
2 Feb 2021
Messages
87
lille-oe.de
We received maybe 10 DSC Urgency All Ships messages when crossing the Minch couple of days ago. All identified to be sent by Stornoway CG (based on MMSI) and setting channel 16. They were sent all at roughly same timestamp, and there was never any voice content to go with it.

They were around the same time Stornoway was reading MSI on their working channels, so maybe somebody pressed the wrong button...
 

wonkywinch

Well-known member
Joined
30 Jul 2018
Messages
1,417
Location
Hamble, UK
Visit site
Had a couple of DSC alerts from weird MMSI numbers (5588?) in the Solent area yesterday. I wish there was an option to have a different tone for buddy calls on DSC vs CG alerts etc, save me reaching for the cancel button automatically then seeing a missed call from a mate!
 

lustyd

Well-known member
Joined
27 Jul 2010
Messages
11,620
Visit site
Did someone accidentally press the MOB button to mark the anchor rather than the mark position button? I believe some units allow automatic transmission of MOB as a PAN PAN.

I certainly wouldn't rule anything out on the basis that you think your install is excellent and the CG didn't receive. If you want to troubleshoot, then throw all assumptions out before starting, otherwise you'll not likely find the issue.
 

ylop

Well-known member
Joined
10 Oct 2016
Messages
1,942
Visit site
Had a couple of DSC alerts from weird MMSI numbers (5588?) in the Solent area yesterday. I wish there was an option to have a different tone for buddy calls on DSC vs CG alerts etc, save me reaching for the cancel button automatically then seeing a missed call from a mate!
Trying to work out if you are more worried about cancelling a mayday where someone is in distress or missing the plan for the pub from your mate? I assumed Solent sailors would all use Whatsapp (or SMS) for chatting to "buddies"?
 

Minerva

Well-known member
Joined
16 Oct 2019
Messages
1,242
Visit site
We received maybe 10 DSC Urgency All Ships messages when crossing the Minch couple of days ago. All identified to be sent by Stornoway CG (based on MMSI) and setting channel 16. They were sent all at roughly same timestamp, and there was never any voice content to go with it.

They were around the same time Stornoway was reading MSI on their working channels, so maybe somebody pressed the wrong button...
We encountered similar on Saturday south of Oban. DSC alarms going off with no message on VHF and no voice message. Very odd.
 

davierobb

Active member
Joined
17 Sep 2005
Messages
414
Location
Prestwick, Scotland
www.guesthouseprestwickayr.co.uk
From the posts above it looks like there was a general DSC issue going on at various West çoast locations on Saturday, I'm happy our system is OK. It would be good if the coastguard could provide updates on any technical issues with their systems.

Thanks for the replies.
 

Eccles

Member
Joined
26 Mar 2003
Messages
149
Location
Jersey, Channel Islands
Visit site
Don't know if this relates to spurious DSC calls but the other week (during the high solar activity) my GPS kept reporting excessive speeds for a split second over the course of 5 hours - my max speed recorded was 3801 kts 😲
 

wonkywinch

Well-known member
Joined
30 Jul 2018
Messages
1,417
Location
Hamble, UK
Visit site
Trying to work out if you are more worried about cancelling a mayday where someone is in distress or missing the plan for the pub from your mate? I assumed Solent sailors would all use Whatsapp (or SMS) for chatting to "buddies"?
I'm satisfied that in a densely populated area like the Solent with active CG stations that they don't need my help acknowledging a mayday, particularly as my boat is stuck in a cradle on the hard at the moment. VHF switched on as I had just replaced the battery in a B&G handset with a Chinese Ebay special and charge time has gone from an hour to two days ;-)

Despite all the DSC interruptions!

bandg.jpg
 

ylop

Well-known member
Joined
10 Oct 2016
Messages
1,942
Visit site
I'm satisfied that in a densely populated area like the Solent with active CG stations that they don't need my help acknowledging a mayday, particularly as my boat is stuck in a cradle on the hard at the moment.
So your buddies call you when you are on the hard? presumably the reason they are missed calls is your can't respond when on shore within the terms of your license ;-)

A busy area makes it somewhat more likely that the person needing help is one of the many vessels you can actually see. It may also make it more likely that the sender is using a h/held dsc at low level (e.g. a kayak) with poor line of sight to a CG mast but good line of sight to you. I think there is a risk of bystander effect - the expectation that someone else will do it in a busy area.

My view is we should always log the details. Then if CG do ask all vessels for information, or the comms are patchy you have it.
If close enough to help you should offer to do so.
If unable to help - but hear no voice comms you should contact CG.

I appreciate you get a lot more maydays than we do so it could be irritating - but your peace being disturbed is still a much better day than even the most trivial thing that causes someone to press the red button.
 

wonkywinch

Well-known member
Joined
30 Jul 2018
Messages
1,417
Location
Hamble, UK
Visit site
The cancelling of DSC alert messages (not maydays) whilst on the hard and my buddy DSC calls are mutually exclusive. Radio was on for receive only testing purposes.

The average day out on the Solent sees at least half a dozen DSC alerts, and a pan/mayday on a fairly regular basis. Maydays certainly get logged.

Then there are the idiots that use Solent CG for radio checks. At least 10 a day?
 
Top