PLB on every lifejacket

A PLB is fitted to to my life jacket and I wear it in all weathers as I sail singlehanded. The reasoning is if I fall in, I stand at least a chance of being found. Without a PLB, I very much doubt I will be found in time as I expect no one will know I went overboard until my boat is found without anyone on her.
 
Interesting - I seem to recall one of the Helo crashes in the North Sea had so many PLB signals it caused confusion. I wonder if they have actually tested what happens when 33 PLBs all go off within 100m of each other, and if the various manual elements along the chain would interpret the signal correctly and not infer a fault!
 
TangaraToo said:
I've spent some time thinking over the options. This winter there will be two of us on board and we intend to sail through the winter months. I expect we will encounter low light, reduced vis, significant weather changes and sea states. If one of us goes overboard the odds of the other keeping the MOB in sight whilst carrying out the necessary actions are slim to zero. Taken the decision to have two of the AIS MOB fitted to our lifejackets which we always wear. Boat has full AIS so chances are increased that we could at least get back to the MOB quickly. 406 type PLB really isn't going to help self rescue which I think is the best chance of surviving a MOB in winter weather. Yes we do also clip on when it's rough or we go on deck but things can happen and having other options once the worst has happened makes sense to me.
Click to expand...

Thanks for this. Having reading it and the recent comparative test, I've just bought Ocean Signal AIS MOB1s for me and my wife. With only the two of us sailing I've always been aware of the difficulty of the person left on board being able to keep eyes on the MOB when there is so much else to do. They look impressive pieces of kit - very clever in sending a DSC alert and AIS position for the plotter. Easy to programme with vessel MMSI and no problem to fit in the LJs. Mine goes into the same side of the LJ as a PLB and a sharp knife both on lanyards. And, before anyone asks, we do routinely wear the lifejackets.

No connection to the company, BTW.
 
Poey50 said:
Thanks for this. Having reading it and the recent comparative test, I've just bought Ocean Signal AIS MOB1s for me and my wife. With only the two of us sailing I've always been aware of the difficulty of the person left on board being able to keep eyes on the MOB when there is so much else to do. They look impressive pieces of kit - very clever in sending a DSC alert and AIS position for the plotter. Easy to programme with vessel MMSI and no problem to fit in the LJs. Mine goes into the same side of the LJ as a PLB and a sharp knife both on lanyards. And, before anyone asks, we do routinely wear the lifejackets.

No connection to the company, BTW.
Click to expand...

Can I expose my ignorance and ask what the DSC on the PLB does??? I do understand that the AIS will show up on your or anyone else's plotter. I like that the MOB1 is automatic

Tudorsailor
 
tudorsailor said:
Can I expose my ignorance and ask what the DSC on the PLB does??? I do understand that the AIS will show up on your or anyone else's plotter. I like that the MOB1 is automatic
Click to expand...

Not a (406) PLB.

Part of the point of the DSC is to address the varying levels of support for AIS MOB beacons on plotters. They're getting better now, but there are still plenty out there that won't raise an alarm, only draw a target which you have to look for. Whereas every DSC VHF will sound a loud alarm in response to a distress signal, and is possibly also more likely to be switched on when offshore than a power-hungry plotter.

If you know that your plotter handles AIS MOB alerts properly including a loud alarm, and you always have it on when under way, then the DSC feature is less valuable.

Pete
 
tudorsailor said:
Can I expose my ignorance and ask what the DSC on the PLB does??? I do understand that the AIS will show up on your or anyone else's plotter. I like that the MOB1 is automatic

Tudorsailor
Click to expand...

The MOB1 will send a DSC alert to your own boats radio provided you have entered the MMSI of the radio in to the MOB1. It does not AFAIK send a general DSC alert.
 
lw395 said:
It seems to me that PLB is not ideal for a person falling out of a tender.
1) the guaranteed response time is too slow
2) the time for the GPS to fix may be too long.
3) it requires that you are conscious and probably wearing your lifejacket.
4) in harbour, there is a possibility of it being dismissed as a false alarm, particularly if the contact details are not up to date.
5) in some mooring areas, would you actually have satellite coverage?
Click to expand...

Probably right, so learn to swim.

Can't get over the attitude that others should get you out of trouble.
After all you're there and, probably, instigated the problem.
 
Quiddle said:
All of which is no doubt true but doesn't equate to the UK Coastguard dismissing a PLB alert, which is the bit that caught my eye.
Click to expand...

I am sure that the Coastguard won’t “ignore” a PLB alert. But there does seem to be a significant risk that it might be quite a long time between falling in, the PLB first transmitting, and the Coatsguard dispatching any assistance. The report on the fishing boat sinking off Mingulay (?) was sober reading - and even if they improve by 90%, there is still likely quite a delay whilst they hand on the information, look up contact details, try phoning etc.
When I bought my first McMurdo PLB for use when singlehanding, my chandlery stated (probably accurately for winter sailing in northern Uk waters) that it “will help them find your body”!

Still very worth carrying. And if like me your first PLB is beyond its stated battery life date but still shows full battery in test mode, rather than spending on a new battery buy a second device and keep the old one as backup.
 
These small AIS MOB devices do look very interesting - and perhaps the best option for crewed boats and those sailing in busy waters with other boats around.
http://www.cactusnav.com/ocean-signal-rescueme-mob1-overboard-p-14638.html

I assume they will work fine with the most recent Raymarine plotters running Lighthouse software, but anybody know if the previous generation Raymarine E series wide is compatible?
 
dunedin said:
These small AIS MOB devices do look very interesting - and perhaps the best option for crewed boats and those sailing in busy waters with other boats around.
http://www.cactusnav.com/ocean-signal-rescueme-mob1-overboard-p-14638.html

I assume they will work fine with the most recent Raymarine plotters running Lighthouse software, but anybody know if the previous generation Raymarine E series wide is compatible?
Click to expand...

Certainly the best option for a boat with capable crew remaining on board.

Almost any AIS display will show the beacon's position, as one of the messages they emit is the same as an ordinary vessel. I don't know whether the E-Series will correctly identify it as a beacon and raise the alarm, but if not there are standalone boxes which connect to the AIS receiver in parallel with the plotter and do the alarm part. Then you look on the plotter for the "ship" which has just appeared astern of you.

Pete
 
dunedin said:
I am sure that the Coastguard won’t “ignore” a PLB alert. But there does seem to be a significant risk that it might be quite a long time between falling in, the PLB first transmitting, and the Coatsguard dispatching any assistance. The report on the fishing boat sinking off Mingulay (?) was sober reading - and even if they improve by 90%, there is still likely quite a delay whilst they hand on the information, look up contact details, try phoning etc.
When I bought my first McMurdo PLB for use when singlehanding, my chandlery stated (probably accurately for winter sailing in northern Uk waters) that it “will help them find your body”!

Still very worth carrying. And if like me your first PLB is beyond its stated battery life date but still shows full battery in test mode, rather than spending on a new battery buy a second device and keep the old one as backup.
Click to expand...

An aside - I ditched my 8 year-old EPIRB, rebatterying it was more than a new PLB, in a bin in Nea Peramos - 36 hours later my wife (the home contact) had a call from Falmouth, asking where my boat might be.
So batteries last longer than stated dates, in this case 60%, and getting round to action takes about a day and a half.
 
Did it take a day and a half? Or did it just get activated when the bin got emptied? And what sort of responsible sailor puts a potentially still active epirb/plb in the bin without a. Removing the battery; b. Deregisterring it.
 
Ready this thread has got me intrigued, interested and alarmed; the latter the foremost.
Have I understood correctly that activating my McMurdo PLB would result in a lengthy delay before alerting the rescue services? Not an immediate alert prompting swift action?

I have always been concerned that removing the lid and aerial and activating the signal would be a fiddly even almost impossible, when in the water, shocked and perhaps injured.

I am therefore very interested to read the reference to the Ocean Signal AIS MOB1.
Is it totally automatic?
If not, what is the procedure for activating it?

As a single-hander I realise that my own AIS receiver might pick-up an alert but be of little immediate use to myself in the oggin.
But a nearby AIS receiver may be able to help.
 
ylop said:
Did it take a day and a half? Or did it just get activated when the bin got emptied? And what sort of responsible sailor puts a potentially still active epirb/plb in the bin without a. Removing the battery; b. Deregisterring it.
Click to expand...

Exhibiting your ignorance, the battery was inaccessible, except with special tools, being a US EPIRB and the deregistration e-mail had already been sent.
The test light had not worked for the previous two years.
The bin was probably emptied 20' after my wife put the EPIRB in it.
 
EPIRB batteries will have some energy in them years after their expiry date. But probably not enough to transmit for 36 hours or whatever the spec is.
PLBs and EPIRBs really ought not to go in general waste a) because of the batteries and b) because somebody is likely to fish them out and set them off.
 
Flica said:
Exhibiting your ignorance, the battery was inaccessible, except with special tools
Click to expand...

Seeing as by that time it was unwanted electronic waste, a hammer would have been a sufficiently specialist tool to open the case and separate the battery from the transmitter. It's well known that EPIRBs and PLBs shouldn't be thrown away without physically disabling them in some way.

Flica said:
The test light had not worked for the previous two years.
Click to expand...

If there's the slightest bit of juice left in the battery, it will still do its best to transmit.

A colleague of mine used to work for an EPIRB manufacturer, and he said they had several cases of beacons that had been left in the sea (either accidentally lost overboard, or left behind when survivors were recovered, or maybe rescue never took place), and naturally stopped transmitting when the battery ran down. Then, weeks later, it would be washed up on some tropical beach and the heat of the sun would eke a few more milliamps out of the battery resulting in a phantom transmission. The drain of sending the pulse would knock it out for the day, but the next morning the same thing would happen, and this could go on for some time. It was a problem because the regular daily transmissions could be mistaken for a shipwrecked mariner carefully turning it on and off to save power, and they modified the firmware to prevent it. But it goes to show that these systems are designed to get the message out at all costs even long after the advertised lifespan.

Flica said:
The bin was probably emptied 20' after my wife put the EPIRB in it.
Click to expand...

But the contents didn't evaporate at that point. It's perfectly plausible for it to take a day or so before someone at a waste processing centre or old-fashioned tip notices a brightly-coloured electronic thing amongst the crisp packets and pizza boxes, and decides to fish it out to see if it's useful, interesting, or worth anything.

Pete
 
Robert Wilson said:
Have I understood correctly that activating my McMurdo PLB would result in a lengthy delay before alerting the rescue services? Not an immediate alert prompting swift action?
Click to expand...

It's against forum practice but always useful to look at what actually happens. PLBs were the primary means of alerting SAR during the Rambler 100 capsize during the Fastnet a few years ago and here is the timeline:

17:40 Rambler capsizes catastrophically
17:45 two PLBs switched on by crew on upturned hull
18:29, MRSC Valentia advised of PLB hit in fastnet area
18:50, Valentia tasks the Baltimore lifeboat
18:51, Valentia declares Pan Pan, tries to contact Rambler 100
19:30, Valentia declares Mayday, tasks helicopter
19:46, Baltimore lifeboat arrives alongside Rambler

So that's two hours and one minute from signal to rescue. There are other examples, including a RIB driver who went in off Pembrokeshire about four years ago, of similar response times.
 
You must log in or register to reply here.

Share this page

Top