So whats the matter with DSC?

[Sans Bateau]

I have just bought a Raymarine 54e DSC radio; I recall a lot of negatives about DSC on the forum, remind me what they are.

The reason for wanting to install a DSC unit is simple, there are usually only the two of us on the boat, so, IF, say one went over the side that only leaves one other to bring boat around for recovery plus drop sails etc. Considering that there may be awfull sea conditions it would be easy to lose sight of casualty. Good practice tells us that CG should be alerted with Mayday ASAP. Is'nt it a lot easier to hit the 'panic' button than to sit there relaying situation, position etc to CG on Ch 16?

Of course before we get into this position the use of harnesses, life jackets etc will make this only ever theory.

 

[StugeronSteve]

Amongst my concerns are a) the number of false alarms that seem to be transmitted; b) poor reliability and function operation on many sets; c) sheer volume of alerts coming in with all ships calls, from Joburg etc, that have you scurrying up and down the companionway silencing the set.

 

[clouty]

quote :-
"Of course before we get into this position the use of harnesses, life jackets etc will make this only ever theory."


Hopefully it is only theory, but s**t happens.

My understanding of the problem is this.

Every DSC set in the area, of a radius minimus 40 NM, will receive distress calls. They will scream insistantly until someone cancels are deals with the distress.

If you are on passage shorthanded, and for whatever reason cannot go below to do this, then the watch below has to, thus being fully awakened.

IMHO, primary safety comes first. Enough sleep, food, knowledge, well found vessel, etc.

DSC could interfere with primary safety on shorthanded, smaller vessels on longer passages.

 

[clouty]

../ so then it may be necessary to turn the set off. Better then to have a regular VHF.

DCS needs some alarm filter in - say you could limit distress signals received to only the surrounding 5NM? Which, in a small yacht, is perhaps all you could help with? Relay is perhaps not so necessary with the better range of these sets. I have no idea whether the above is technically feasible, however.

 

[AlexL]

Unfortunately DSC is fantastic in theory, BUT the alarms are very annoying, and have to be manually cancelled. Fine if its a Mayday as not too many of these are around, but I'm getting DSC alarms associated with the CG all ships inshore water forecasts, and dutch CG navigation warnings. And this is before its even officially mandated. Whats it going to be like in a few years!
My solution is for my new boat I have bought the Raymarine 240DSC which has a separate speaker and mobile phone style handset, which is going up by the helm so the DSC alarms can be cancelled by the helmsman without waking up everyone below.

BTW you still have to send out a voice mayday so the actuall transmission procedure takes longer!

 

[jimbouy]

[ QUOTE ]


BTW you still have to send out a voice mayday so the actuall transmission procedure takes longer!

[/ QUOTE ]

Er. That's the procedure. But are we saying the life boat won't be launched until you've made the voice call?

and I'm not advocating failure to follow procedure. But if a situation came about where you couldn't make the voice follow up straight away.... what would happen?

 

[Sans Bateau]

My understanding is that you either hit the panic button or select your particular distress, which will alert CG of your current problem, so no dialog should be needed.

The other issues raised I agree with, I have sailed on boats with DSC and an alarm going off at 0300 when you are asleep is enough to stop your heart!

Come on CG, take note the system needs a mod.

 

[BrendanS]

The correct procedure, as taught on DSC vhf courses, is that after you hit the panic button, the set will go automatically to CH16 where you should make a normal voice Mayday call, without waiting for any DSC acknowledgement

 

[Robin]

Fine principle poor practice

Pressing the button will transmit your Mayday and your position (if the GPS is linked to the DSC) but you will then get voice calls so will still need to be monitoring the VHF as before.

The alarm tones will drive you crazy! You cannot adjust the volume of the alarm except by switching the set off altogether, an option we have often taken. These are rarely if ever genuine Mayday alarms (which would be acceptable and indeed very justified) but are usually to proceed an announcement that someone has decided needs to be heard by everyone within an 80 mile radius! The alarm is used to warn of a weather bulletin from the CG, a Nav warning from a Traffic Control Centre (like Joburg Traffic Contol on Cherbourg peninsular) or even from a RN vessel. Many of these 'routine' alarms are repeated and repeated, Joburg likes to do it every 20 minutes or so. When an alarm goes off, you can only silence it by pressing a button on your set which is then hijacked by the transmitting station and switched to their chosen channel - even if you were in the middle of listening say to an important forecast on another channel as happened to us now 3 times! What is really irritating is that you may not even hear their announcement in 'voice' because the receive channel doesn't receive voice over the same distances that the DSC digital alarm signal on CH70 does! We had many instances last year of receiving alarms and being switched to CH80 (Joburgs usual) when we heard nothing on voice because we were over a hundred miles away - but we received the wake up call!

IMO the repeated use of alarms is forever calling wolf and the result is counter productive, sets get turned off. We no longer have ours on if anyone is sleeping below and we will turn it off if we start hearing 20 minute repetitions of routine calls, after which it probably stays off. I will probably refit our old non-DSC set to use as a voice monitor only, we can do that as we have a 2nd VHF aerial anyway already wired, the DSC set would just be there 'in case'. Those involved with this (CG/radio Licencing peeps) seem very unconcerned about it, not very good if you want my opinion!

 

[webcraft]

Re: Fine principle poor practice

Luckily we don't get many DSC alarms up here, nor were they a nuisance on our trip round Ireland last Summer. If/when they get to be an annoyance the set will be kept switched off when we don't want to be disturbed.

Will we then be in breach of what I believe used to be a requirement to keep a listening watch if the equipment was on board?

- Nick

 

[Sans Bateau]

Re: Fine principle poor practice

I was looking forward to this! Can you still buy a set that is non DSC? We have to replace the radio and this looked like the way to go.

The end of your last paragraph, have you contacted the various authorities? The situation that you have described, surely cannot continue.

 

[tome]

Re: Fine principle poor practice

A good summary Robin, and I agree. The DSC equipment specification for leisure craft has to be one of the most senseless I've encountered, and both the regulators and manufacturers are firmly burying their heads in the sand.

I'm tempted to open mine and add a volume control directly to the speaker so that I can regulate the banshee wail of the alarm. Better to violate the equipment type approval than to switch it off.

 

[wicked]

The number of alarms will drive you crazy. I often sail singlehanded and have been in shipping lanes when it was too rough to safely leave the helm to shut up a DSC alarm. Drove me crazy, so I have now moved the DSC set to a position whereby it can be swung into the companion way so I can reach it singlehanded.

If you have an early version of the Silva S15 DSC radio with inbuilt NAVTEX then you have yet more problems - if you leave the set switched on in a marina to collect NAVTEX messages while the boat is unattended and a DSC alarm goes off, someone will surely break into your boat to shut it up. Similar problem is fou are sleeping on the boat and you want to leave the set on to collect overnight NAVTEX - pretty scary when the DSC alarm goes off!.

I'm now on my 3rd replacement Silva S15 DSC (cos they are rubbish!) and they have finally changed the software so you can direct the output to either the internal speaker, external speaker or both. If you select the external speaker then unplug it it at night or when the boat is unattended it solves the NAVTEX problem!.

Dave.

 

[sailorman]

Re: Fine principle poor practice

YES BUY A S/HAND SET /forums/images/graemlins/grin.gif

 

[Oldhand]

Don't have to go below to cancel or read a DSC alarm. A full control handset next to the helm is the answer. /forums/images/graemlins/laugh.gif

 

[Koeketiene]

You can solve any problem if you throw enough money at it /forums/images/graemlins/grin.gif

 

[Marsupial]

Re: Fine principle poor practice

Yes you can its one of the ICOM range has two parts, VHF and DSC - its legal to buy and instal only the VHF module.

 

[Robin]

Re: Fine principle poor practice

Through the Forums and various PMs the questions were discussed with Mike Martin from the Radio Licence people, a Coastguard and Jon Brooks at Icom. All made noises about raising the question and the points made on various postings before, but so far nothing has happened. I get the feeling that they think this is a non-problem, leave it and it will go away. I guess it will go away as more and more either don't join the DSC club, opt to leave it or just switch off!

 

[claymore]

Re: Fine principle poor practice

Well Nick - I'm glad you said that. The old cats whiskers is getting on in years and I was thinking of replacing it but I think we'll hang on until it dies.
You've just saved me £250. May I buy you a wee nip?

 

[Sans Bateau]

Re: Fine principle poor practice

Our old Kelvin Hughes 'Husan' radio in our old boat, in the right weather conditions would pick up from the Solent, Dover, St Peter port, and even once heard Swansea! Should have kept it!