Hypothetical DSC Mayday Question - WWYD

[Mark-1]

You're in distress and send a DSC distress message.

Shortly afterwards a vessel 4 miles away sends a DSC Distress message.

Do you relay it?

My gut feeling is no, it could add confusion - maybe another station might think you've transmitted your mayday by mistake when you merely meant to relay the other message.

 

[sarabande]

Done properly, each Distress/Mayday call will incorporate the MMSI and callsign. There should be no confusion at the CG station.

If there is no reply to the other Distress call within say 5 mins, then if you are able to help try a Ch16 call to them, then try the DSC Urgency alert followed by standard Mayday Relay. If you are in no position to offer help, then keep off the channel.

 

[lpdsn]

You're in distress and send a DSC distress message.

Shortly afterwards a vessel 4 miles away sends a DSC Distress message.

Do you relay it?

My gut feeling is no, it could add confusion - maybe another station might think you've transmitted your mayday by mistake when you merely meant to relay the other message.

You would hopefully be talking to the coastguard anyway after your own distress message.

Apart from that what makes you think your DSC range is greater than the boat 4 miles away? Since I've started feeding the data from the radio into OpenCPN the impression I've got is that DSC maydays have far greater range than VHF voice communications.

 

[alant]

You're in distress and send a DSC distress message.

Shortly afterwards a vessel 4 miles away sends a DSC Distress message.

Do you relay it?

My gut feeling is no, it could add confusion - maybe another station might think you've transmitted your mayday by mistake when you merely meant to relay the other message.

If your already in distress, you have enough to worry about anyway.

 

[capnsensible]

If your already in distress, you have enough to worry about anyway.

Imagine the arguments with modern people. 'My distress is bigger than your one, me first.'

 

[Mark-1]

My gut feeling is no, it could add confusion - maybe another station might think you've transmitted your mayday by mistake when you merely meant to relay the other message.

I've changed my mind. Any confusion would be caused by proximity, not by the relay.

 

[sarabande]

I've changed my mind. Any confusion would be caused by proximity, not by the relay.

Two different DSC alerts, each with unique MMSI and position ? Followed by a Mayday with more info. What's to confuse ?

 

[Mark-1]

Two different DSC alerts, each with unique MMSI and position ? Followed by a Mayday with more info. What's to confuse ?

If I received two maydays a few seconds apart and in close proximity to each other I would certainly be considering the possibility that it was two reports of the same casualty.

I'd go a bit further, I think finger trouble with the radio would be a likely cause of the scenario I describe. Second boat intends to relay, but sets off his own Mayday instead.

If I was dealing with the incident, if I could contact both vessels, I'd be checking.

 

[lpdsn]

If I received two maydays a few seconds apart and in close proximity to each other I would certainly be considering the possibility that it was two reports of the same casualty.

I'd go a bit further, I think finger trouble with the radio would be a likely cause of the scenario I describe. Second boat intends to relay, but sets off his own Mayday instead.

As others have said, the MMSI would mean they appeared as two maydays. I did see one appear off the coast of South America once though and I didn't hear Belfast Coastguard respond. I guessed it was somebody trying to do a test with false Lat & Lon but listened out for a while and heard nothing.

I'm sure if the second vessel was finger trouble the coastguard would soon sort it out and withdraw the two-for-the-price-of-one offer from the RNLI.

You do wonder though why a second vessel four miles away would be attempting a DSC Mayday Relay. You'd think they'd just listen out and proceed toward the mayday until they hear the coastguard dealing with it. Or if not try to contact the coastguard or vessel themselves.

 

[alant]

As others have said, the MMSI would mean they appeared as two maydays. I did see one appear off the coast of South America once though and I didn't hear Belfast Coastguard respond. I guessed it was somebody trying to do a test with false Lat & Lon but listened out for a while and heard nothing.

I'm sure if the second vessel was finger trouble the coastguard would soon sort it out and withdraw the two-for-the-price-of-one offer from the RNLI.

You do wonder though why a second vessel four miles away would be attempting a DSC Mayday Relay. You'd think they'd just listen out and proceed toward the mayday until they hear the coastguard dealing with it. Or if not try to contact the coastguard or vessel themselves.

But they themselves have also made a distress call, so unlikely to proceed toward the other.
Also there would be a mayday silence, with cg trying to contact them (the OP's vessel).

 

[lpdsn]

But they themselves have also made a distress call, so unlikely to proceed toward the other.

I was thinking in terms of Mark-1's revised scenarion in post #8 where he has the second Mayday as a attempted Mayday Relay with finger trouble - hence questioning motive of DSC Mayday Relay so close.

Also there would be a mayday silence, with cg trying to contact them (the OP's vessel).

A subsequent vessel is still allowed to put out its own mayday, assuming genuine, even with a SEELONCE MAYDAY. You could just imagine the coastguard "Sorry sir, only one at once. Please join the end of the queue."

 

[alant]

I was thinking in terms of Mark-1's revised scenarion in post #8 where he has the second Mayday as a attempted Mayday Relay with finger trouble - hence questioning motive of DSC Mayday Relay so close.



A subsequent vessel is still allowed to put out its own mayday, assuming genuine, even with a SEELONCE MAYDAY. You could just imagine the coastguard "Sorry sir, only one at once. Please join the end of the queue."

Yes, I know you can still put out your own mayday, you'd be bloody stupid not to, but should be careful about pratting on the airwaves about another mayday, when you should be listening for a cg response to yours.

 

[[70521]]

If your already in distress, you have enough to worry about anyway.

+1

When the bovine excretia hits the fan you are your number one priority.

 

[ShinyShoe]

I do love a hypothetical scenario on a forum! Bad enough you are in a mayday, bad enough someone else is too, good that your imminent danger is not quite so imminent you are worrying about someone else, bad that they can are out of range but luckily you were.

Assuming you've sorted comms to CG for you, I'd imagine the conversation would be something like this:

(after waiting the requisite time to hear a response)
Belfast Coastguard this is Mayday MyYacht, over
Mayday MyYacht, this is Belfast Coastguard go ahead, over
Belfast Coastguard this is Mayday MyYacht, we have received a separate Mayday from a vessel about 4 miles West of us . We have not heard an acknowledgement on 1-6. Vessel name is MotorVessel OverThere Do you need this relayed? over

I'd say that is perfectly clear this is a different incident. There becomes a few possibilities:
- Yes they have heard it but are responding from a different mast to avoid confusion with your incident* (at 4miles unlikely TBH)
- Yes they have heard it, but have responded initially via a different channel to avoid confusion (I think more likely they move you elsewhere, or them after the initial response - but in a modern DSC world it would be possible for them to have contacted the vessel on another channel)*
- Yes they are in contact via mobile phone*
- No - please relay it to us.
* All will get a CH16 mayday relay from CG once they have the initial plan in place.

I've heard a first mayday and then a second mayday a mile or so away about 5minutes later. Trigger happy attempt to relay - but it was initially handled as a separate incident, but obviously with a suspicion that is what had happened.

 

[Uricanejack]

Done properly, each Distress/Mayday call will incorporate the MMSI and callsign. There should be no confusion at the CG station.

If there is no reply to the other Distress call within say 5 mins, then if you are able to help try a Ch16 call to them, then try the DSC Urgency alert followed by standard Mayday Relay. If you are in no position to offer help, then keep off the channel.

I suspect this answer is technically correct.

I wondered about the practicality of this hypothetical scenario.
I can think of several real life scenario which would fit the description.
Eg. Fast Net Race in was it 78 or 79. Multiple distress calls. Of similar nature from similar vessels in relatively close proximity.

Practicality of the situation. The Vessel in Distress has enough on its plate and will not be able to assist the other nearby vessel possibly in quite a similar situation. Beyond perhaps mentioning they are part of a race and their pals calling for help to.
The communication will be quite overwhelming just for your own vessel. Without trying to add a relay for another. In the unlikely event you were aware your pals boat had not been heard. Pass it on as best you can.

Or after a collision. (ok maybe not 4 miles apart) Two separate vessels both potentially in distress. Possibly only one is able to make the distress call.

Many years ago. A friend of mine. Ex rescue swimmer, received an award. After deploying multiple times in one night after storm force winds overwhelmed a number of small fishing vessels. Several small vessel in the same general area all in distress.

Having once called a Mayday Relay. I found, I was unable to effectively carry out the correct procedure. I just did not have enough hands. Trying to respond and communicate at the same time was not possible. I wasn't in distress.

You just do the best you can in the circumstances.

How assets are deployed in response will be up to the RCC.

 

[Uricanejack]

Two different DSC alerts, each with unique MMSI and position ? Followed by a Mayday with more info. What's to confuse ?

Assuming both vessels have DSC.

 

[sarabande]

You mean, as in the OP ?

 

[Uricanejack]

If I received two maydays a few seconds apart and in close proximity to each other I would certainly be considering the possibility that it was two reports of the same casualty.

I'd go a bit further, I think finger trouble with the radio would be a likely cause of the scenario I describe. Second boat intends to relay, but sets off his own Mayday instead.

If I was dealing with the incident, if I could contact both vessels, I'd be checking.

Might be. Might not be.
Many years ago, I was having a cup of tea late at night after a family get together. When somebody. chucked a Molotov cocktail into our garage.
Took a bit to realise what the bang was. We had a few exciting moments. Trying to convince my father in law going into the garage in his PJ's with a garden hose was a really bad idea. While my sister in law called 911.

We were very pleased at the FDP response. The Fire Truck arrived very quickly. along with the rest of the first response.
The Fully suited Fire Men hoped out and started taking the mickey out of my Father in Law for his PJ's and garden hose. Mentioning the ladder burning in his garage looked remarkably like a fire dept. ladder.

They had a young Probey with them who was left to pull a hose and start on the burning garage.

Naturally my wife had put the put kettle on and made tea, Which she now poured for the Fire Men. Along with her sister passing round some biscuits.

About this time a second fully crewed Fire Truck Arrived. The Fire men all came for tea and biscuits and joined in teasing Dad about his PJ's and Garden Hose. While their Probey pulled out a second hose.

The Probies got lots of advice. While the two crews enjoyed their tea. Both crews were having a great laugh at having been called out the FDP Chiefs house. At his expense.

When an unfortunate chap from the exact same house number on 1st avenue instead of 3rd avenue came to ask why we had two fire trucks at our fire while he didn't have any at his.

Fortunately although they didn't get to finish their tea they did manage to put the other chaps fire out just in time before it spread to his house.

We later heard, Somebody had chucked 6 Molotov's into 6 different Garages. The first Fire Truck had been dispatched to the 1st fire, on spotting our fire on route assumed there was an error in the reporting of the address.

 

[sarabande]

That's a far more exciting street than the one I live on ! But your point about two incidents geographically close together is well illustrated.

I always understood that DSC messages include the Lat Long as well as the MMSI number. If so, then CG will see that there are two separate events ?