Has DSC proved to be a bit pointless?

[Mark-1]

then find that the Chardonnay is warm!

That's when you hit the red button.

 

[alant]

That's when you hit the red button.

Not very far from the truth.
I well remember listening to a conversation between a 'very worthy gentlewoman of Lymington' & Solent CG some years ago. She had run aground in the Lymington River & called a mayday. The patient CG, tried his best to deal with her 'emergency' & her strident demands that someone should be tasked to rescue her, "this instant". Eventually, much like Mrs Bouquet (bucket ), she advised that it was imperative she was taken to shore, because "I'm expecting the Vicar for Tea".

 

[Daydream believer]

My AIS has a red button as well. No one has mentioned that addition. Do others have them?
when i bought the set it came as part of the. "run sillent" switch which i bought as an extra so i could avoid transmitting in conjested waters but still receive. Seemed a sensible option to have

 

[[70521]]

My AIS has a red button as well. No one has mentioned that addition. Do others have them?
when i bought the set it came as part of the. "run sillent" switch which i bought as an extra so i could avoid transmitting in conjested waters but still receive. Seemed a sensible option to have

My set has an option to send a mayday, BUT and it is a large but, in the manual it clearly states that it is not part of GMDSS! I don't think I'll risk it.

 

[[163233]]

My set has an option to send a mayday, BUT and it is a large but, in the manual it clearly states that it is not part of GMDSS! I don't think I'll risk it.

Surely if you actually need to send one then you'd use every means available?
What's the risk?

 

[Daydream believer]

My set has an option to send a mayday, BUT and it is a large but, in the manual it clearly states that it is not part of GMDSS! I don't think I'll risk it.

Presumably it would send out some sort of extra flash to high light it on other vessels screens this would make search and rescue easier in the event of dismasting ( mine is on the rail) plus other vessels might investigate. I am not sure if it sends a mayday note in the description screen . Have not got round to investigating the instructions that far as i have other means of distress calling. Plus in a lot of places where i sail the in date flares might actually work in spite of some forumites opinions

 

[johnalison]

It would make sense for AIS transmitters to have the capacity to indicate distress, so that apprpriately-fitted receivers could locate the casualty. I haven't followed the technology but it sounds as is something of the sort is happening. Another possibility would be if plotters were able to show the site of a casualty directly from the postion received by a DSC call. This may also already be available I suppose, but not on my older set.

 

[maby]

It would make sense for AIS transmitters to have the capacity to indicate distress, so that apprpriately-fitted receivers could locate the casualty. I haven't followed the technology but it sounds as is something of the sort is happening. Another possibility would be if plotters were able to show the site of a casualty directly from the postion received by a DSC call. This may also already be available I suppose, but not on my older set.

Modern plotters certainly do show the location of a DSC call. I'm pretty sure that the AIS protocol can also include data to indicate distress. A couple of weeks ago our plotter popped up a box on the chart indicating that there was a MOB test in progress there.

 

[Pavalijo]

I made a call for the first time last month when crossing Biscay. I noticed a Brittany ferry doing 20kts with a CPA of between a hundred metres and 0.7nm from about 80 minutes out until I called him by DSC with a little under 20 minutes to go to CPA then of 100m - 0.2nm (question - should I have done this earlier?). It had been on a course of 170 all that time. The call just rang on and was not answered, but the course immediately altered to 174, and the CPA ended up a little over 1 mile IIRC.

My AIS was transmitting and my radar reflector hoisted. It seemed to me that I hadn't been seen. Naturally I could have called up on 16 by name from the AIS info, but thought that a DSC call was more likely to be noticed - which it seemingly was, but the captain did not have the courtesy to acknowledge.

I do mean to write to Brittany ferries to seek an explanation, but as a relative newcomer wondered if this was to be expected?

After reading this thread I must check if my radio function is linked to the plotter - Raymarine plotter is fairly new but the radio several years old (Raymarine 54e) , so not sure. I am not a technofile and was disappointed when the new plotter and radar came with virtually no user instructions that I can read in bed!!

 

[doug748]

...............After reading this thread I must check if my radio function is linked to the plotter - Raymarine plotter is fairly new but the radio several years old (Raymarine 54e) , so not sure. I am not a technofile and was disappointed when the new plotter and radar came with virtually no user instructions that I can read in bed!!

Raymarine have old manuals on the website, see here:

https://raymarine.app.box.com/s/55w633qmoxe4h6v5nwgx/file/3273097377

To get direct calling via AIS you may well have to buy a complete new set of kit, probably not worth it for most.

 

[[70521]]

Surely if you actually need to send one then you'd use every means available?
What's the risk?

From the manual of my AIS transcever

Send MAYDAY

Sends a MAYDAY broadcast safety message to all AIS-equippedvessels within radio range. You can only send a broadcast safety
message once per minute. Before transmission, you will be required to
confirm your selection.


Important: AIS broadcast safety messages may not be received,
recognized or acted upon in the same manner as Global Maritime
Distress Safety Systems (GMDSS) messages by competent authorities
or maritime first responders in your location. This feature must not be
relied upon as the primary means for broadcasting a distress situation
nor used in lieu of GMDSS, such as Digital Selective Calling radios.
Nonetheless, AIS is an effective means to augment GMDSS and
provides the added benefit of being ‘seen’ (on radar or other displays),
in addition to being ‘heard’ (via broadcast safety messages) by other
AIS users within radio range.


Do not use this as your only means of communicating a MAYDAY.

The risk is that it cannot be received or acted on, so a VHF DSC Mayday is my primary way of asking for help, a AIS Mayday call is a nice add on AND flares also have their place.

 

[lpdsn]

From the manual of my AIS transcever


The risk is that it cannot be received or acted on, so a VHF DSC Mayday is my primary way of asking for help, a AIS Mayday call is a nice add on AND flares also have their place.

I think JBJag27 interpretted your "I won't risk it" comment as meaning you wouldn't use it in an emergency - to be honest so did I. Difference between using it if available and relying on it as your only means of raising a Mayday.

 

[ShinyShoe]

Wow 8 pages and I'm not sure much of the OP's questions have been answered!

When it came out I thought it was a great idea, especially the red button and linking it to gps. The idea of a quick press of a button to get help was great. However over time I suspect there are thousands of radios with an mmsi number linked to previous owner of the radio, or installed in a different boat. At best that seems to me to make the whole DSC concept a bit pointless, whilst potentially dangerous in an emergency situation.

I think others have explained if the radio stays in the boat the MMSI should be transferred. In that scenario even if it isn't and you only hit red before loosing contact - I'm not sure what danger exists. A LB or Helo will be tasked to your position from the red button. They may try calling the old out-dated shore contact to see if they have contact with yo, but help will be tasked. I guess there is a possibility they contact the shore contact and instead of saying "Erm I sold that boat 3 years ago they say, no my [new] boat is safely tucked up in the marina" which could result in assets being cancelled. I expect there are some safeguards against that - and ultimately if a position was given with the distress alert that wasn't the marina I'd expect they will want someone to take a look. At the very least they will probably send a coast rescue team to the marina to check out what went on. Unless the old owner also put the same name on the new boat they wont find it and some phone calls will take place.

Similar if you sell your radio / take it to your new boat. There may be confusion which boat is in distress. If it gave a position - help is heading to that position.

Both my current radios have an mmsi number linked to previous owners. My last three boats were the same. I suspect all my old radios will still have mmsi numbers linked to me.

Tell Ofcom

What was the idea behind not allowing users to change the details whenever the needed to change them?

Two fold - Cyber Security! Making it easy to switch identity makes it easy to cloak another vessels identity and pretend to be in distress etc. Imagine the impact if you copied a Brittany ferry's MMSI and transmit a red button from your set claiming to be on fire or sinking. Huge amounts of resource will be sent to a non-incident
- Set swapping. To avoid you keeping the radio on one boat but taking it on another on say a charter etc. Then keying in the wrong MMSI and causing confusion.

I don't think I have ever called anyone using their mmsi number. I just phone them.

Requires you know their phone number.

Even going back to when DSC arrived on the scene when I bought into the idea, I quickly found that I couldn't be bothered with the faff finding their mmsi number and just called them on Chan 16.

DSC came in as mobile phones hit mainstream. No-one remembered mobile numbers and phones had phone books. So do yachts, but even entering someone into one is a pain... ...not aware of any set that allows you to save the calling vessels MMSI etc.

Before the advent of Mobile phones when you couldn't get a word in edgeways on CH16 on a Sunny weekend on the Solent calling mates on VHF with DSC would have been very handy. Now everyone has a mobile phone CH16 is pretty quiet so I guess the problem DSC calling solves has gone away.

Some might suggest... ...DSC did that not mobile phones ;-) We simply don't know how many people DSC call... ...but I suspect you are right.

Red button is probably still useful, although depending on the situation, I might reverse the procedure and have voice contact first and then hit the button to quickly pass on position etc. (So the receiver knew it was a call and I had the reassurance that someone was aware of the problem.)

I think you'll find MRCC would prefer you do it the correct way. If you voice call them and there is uncertainty on your position they will ask you to red button. But the question would be WHY would you do it backwards. What receiver knows it is a call? And What receiver has reassurance? A random other boat who may or may not have been properly listening on 16?

The red button gets all the crucial info to the people that matter in <10 seconds, with no risk of transcription errors. It makes everyone listen up (acknowledging the point made by others that some may treat it as nuscience and cancel it). There are situations where hitting red has made a difference and others where placing a voice call without red has been the WRONG thing to do. (Fishing boat off scotland placed a partial voice call. Never pressed red. Search took place in wrong place).

Am I right in thinking that hitting 'acknowledge' cancels someone else's DSC mayday? Pretty sure I am.

This has been answered by others but for clarity ACK on a Class D (leisure set) just makes the alarm silent. ACK on a Class A set (which a standard VHF certificate doesn't allow you to use) - does send the acknowledge message which stops the set re-sending it. Close to shore a ship with Class A will not ACK unless the CG are not. But if they do, their higher level of training teaches them what to do. Class A sets also allow a proper Mayday Relay - your class D set doesn't and you'll have been trained to send an Urgency Message with a voice relay. Boats with Class A probably have Sat Comms and so can always relay to a shore station.

Many sailing in familiar waters, like the Solent, do not switch their gps on, rendering it useless in terms of dsc sending position. You, as skipper may remember your gps isn't on & can rectify in an emergency. However, if you are rendered helpless or mob, will your crew be aware? Maybe worth telling them.

I'd want that GPS always on. So I'd either always turn it on, bay a VHF with inbuilt, install a separate GPS for the task (<£30)

My AIS has a red button as well. No one has mentioned that addition. Do others have them?
when i bought the set it came as part of the. "run sillent" switch which i bought as an extra so i could avoid transmitting in conjested waters but still receive. Seemed a sensible option to have

Presumably it would send out some sort of extra flash to high light it on other vessels screens this would make search and rescue easier in the event of dismasting ( mine is on the rail) plus other vessels might investigate. I am not sure if it sends a mayday note in the description screen . Have not got round to investigating the instructions that far as i have other means of distress calling. Plus in a lot of places where i sail the in date flares might actually work in spite of some forumites opinions

It would make sense for AIS transmitters to have the capacity to indicate distress, so that apprpriately-fitted receivers could locate the casualty. I haven't followed the technology but it sounds as is something of the sort is happening. Another possibility would be if plotters were able to show the site of a casualty directly from the postion received by a DSC call. This may also already be available I suppose, but not on my older set.

They work like a AIS PLB would. They will pop up on your plotter as a distress. But there is no voice message, no nature of distress. The range is less than VHF. It would be very useful for helping a LB or HELO zoom in on you for final mile type stuff.

Would another boat investigate? I'd be worried about the whole crowd effect issue. So you are in the Solent and press AIS distress. So many other boats in the Solent that everyone with AIS is assuming it must be a test or something as no-one else is doing anything. So everyone carries on regardless. In a quiet area... ...far less chance of there being a second boat with AIS.

Its not a bad plan to have - just a bad plan if it is your primary means of contacting help.

I made a call for the first time last month when crossing Biscay. I noticed a Brittany ferry doing 20kts with a CPA of between a hundred metres and 0.7nm from about 80 minutes out until I called him by DSC with a little under 20 minutes to go to CPA then of 100m - 0.2nm (question - should I have done this earlier?). It had been on a course of 170 all that time. The call just rang on and was not answered, but the course immediately altered to 174, and the CPA ended up a little over 1 mile IIRC.

Why should you have done it earlier? 20minutes out seems fine to me - time for you to tack if need be.
They may have seen you and hoped you'd avoid them (tut tut).

I do mean to write to Brittany ferries to seek an explanation, but as a relative newcomer wondered if this was to be expected?

It may not be uncommon. What did you want to say? There may be a question of what if you'd been calling for another purpose. A second call after the change of position might have resulted in contact. There is a concern about making verbal plans to avoid risk of collision. I suspect they can avoid risks of saying they are altering course to port/starboard being interpreted by you as a request for you to do so.

After reading this thread I must check if my radio function is linked to the plotter - Raymarine plotter is fairly new but the radio several years old (Raymarine 54e) , so not sure. I am not a technofile and was disappointed when the new plotter and radar came with virtually no user instructions that I can read in bed!!

It may be connected but you need it to have both an NMEA IN and NMEA OUT on the radio. I doubt the 54e has NMEA out.

 

[Pavalijo]

Well thanks for answering my queries Shiny!

 

[maby]

At risk of resurrecting an old(ish) thread, we demonstrated yesterday the value of DSC. We had met a German couple at our marina earlier in the week and missed the opportunity to say goodbye to them when they set sail. We had a couple of important messages to get through to them and no phone number that we could call them on. I knew that they had left quite recently, so switched on the plotter, gave it a couple of minutes to find them on AIS and verified that they were still in range. I tried a call on 16, but they didn't notice it. I got their MMSI from the AIS and transferred it to the radio, sending a routine traffic request to their radio - within thirty seconds I had them on the radio, we had switched to a free channel under DSC control and I was able to get our messages through.

 

[Topcat47]

Not quite pointless. I had a near miss with a hovercraft yesterday, reported it to Solent Coastguard and this morning the MCA phoned me on my mobile to discuss the incident. All traced via my Radio licence and the CG66 registration.

 

[Daydream believer]

Not quite pointless. I had a near miss with a hovercraft yesterday, reported it to Solent Coastguard and this morning the MCA phoned me on my mobile to discuss the incident. All traced via my Radio licence and the CG66 registration.

So have you been charged?

 

[BelleSerene]

I bought my first DSC C.2005 and sent my first call to Holyhead Coastguard. Their response: Station calling HH Coastguard with mmsi xxxxxxxx give your vessel's name, over.
Never bothered since.

I wonder how you expected them to address you?

 

[Praxinoscope]

Having just changed boats, I have to re-register the MMSI of the radio on my new boat, no problem, the real pain is that I have to return my hand held to the UK service centre pay some exhorbitant fee to have the MMSI reset.

 

[chewi]

I wonder how you expected them to address you?

You would expect the CG to have a link from the MMSI via MARS database to know the registered vessel name, but equally so you could expect them to confirm it. so not bothering with it anymore for that reason is perhaps premature, but I don't use my DSC either., except the (hopefully not) red button.

Even the red button is flawed.
You cannot define your own likely emergencies at installation (eg Diver lost/overdue)
and choosing from them is unfamiliar in a stressful situation.
No of persons on board should be asked for on each switchon.

For infrequent use the system has to be familiar. The user interface could become more phone-like now, but at the time of DSC introduction (pre smart phones) they weren't so familiar either....