OCC Forums

Personal Locator Beacons (PLBs)


By alshaheen - 13 Oct 2012

I want to start a discussion on this subject, which I have only just strated to research.

There seem to be three main types of PLB.
1. Personal EPIRB devices. Here the signal from the PLB is sent to the COPASS SARSAT satellite system and then relayed to an MRCC, like any EPIRB signal. The disadvantage is that the any remaining crew aboard the boat are not alerted about the MOB and it could take many hours before a ship is diverted to perform a rescue, by which time the casualty may have drowned or be hypothermic.

2. AIS type systems. These give out an AIS transmission from the MOB and may be picked up by the yacht on their AIS receiver. For those of us who have their AIS displayed on a chart plotter, and have the plotter turned off on ocean passages to save on power, it will take some time to fire up the plotter and get a bearing and distance to the MOB.

3. Proximity types. These work when a crew wearing a personal fob, goes out of range (20 ft) of the transmitter unit.They give an audible alarm and the unit can display boat position at the time of MOB.

Does anyone have personal experience of any of these PLBs?? Are there any other types available?
By robwithers - 16 Oct 2012

I investigated these products last year before doing the ARC.

After some research we bought one of the proximity type alarms. Everybody wore a fob, and if it went more than 30 feet from the chart table, a loud alarm would go off. Unfortunately it was completely useless. The alarm would go off whilst sitting in the cockpit, in the rear cabin - in fact anywhere further away than 6feet. The alarm was indeed very loud, but we couldn 't put up with the constant false alarms and never managed to keep it on for more than 15 mins before getting fed up with it. I put a video of it failing (in our kitchen after removal from the boat) on youtube here: http://youtu.be/fvRzQhmEL9E In the end, we returned it and got our money back.

The AIS beacons were not on the market in the UK 18 months ago - now I think I would get some of this type
By simoncurrin - 16 Oct 2012

We too had the same problem with false alarms with the proximity (Raymarine) system on passage to the Lofoten Islands in 2007 and haven 't used them since. The false alarms do, however, seem to have been less frequent than those encountered by Rob. They work on bluetooth and it may be that more modern versions are more reliable.

On the ARC in 1999 a Norwegian went overboard wearing his life jacket and was picked up 16 hours later alive and well apart from sunburn. Had the AIS system have been available at that time then one would imagine the search would have been much shorter.

It 's a shame nobody yet seems to make a device with all 3 modalities built in (perhaps with strobe, whistle and marine vhf too)! Maybe there is a business opportunity there!

By fgrennie - 16 Oct 2012

We used the proximity fob type alarm and as already mentioned they are not very good. False alarms were regular especially if the person went to the bow of the boat. One night while Mark was on watch he had to go up forward to sort something out and the alarm went off, I got up looked in the cockpit no Mark so went into panic mode. All I can say is it can cause a lot of unnecessary stress.
By mikeaclark - 19 Oct 2012

In agreement with others, our Ray Marine fob was useless for same reasons
By DariaBlackwell - 20 Oct 2012

We have a 406 mHz type PLB (original ACR model) and a proximity type with directional radiofrequency finder. Fortunately, we have not had need to test either under emergency circumstances. We don 't have any false alarms with the old proximity type. It 's being retired.

The PLB is great because we can use it while skiing and hiking, too. The main difference between the PLB and an EPIRB is registration. EPIRB belongs to the boat. PLB belongs to the person. I have been reading that the SPOT has some problems in poor reception in some areas and increasing interference from outgoing messages (they can send periodic position reports). See PS articles about some other very valid concerns


I think the AIS enabled ones sound interesting.
By mikeaclark - 21 Oct 2012

Another use for the proximity type locator becon is as a dingy theft alarm. We put a fob in under the dingy seat at night. Should the dingy either come loose or be takenit will sound an alarm. Just another use for the same equipment if you have it.
s/v Waterwitch
By simoncurrin - 22 Oct 2012

What an excellent idea.
By swakeman - 24 Oct 2012

With the advent of the new AIS type PAB 's(personal AIS Beacon), Polly & I have also been re-considering what to use. We used to have the 121 mhz type with RDF, and now have the (first gen) ACR 406 PLB 's. As mentioned, the 406 PLB 's are attractive as we can use them hiking, mtn climbing, etc. Our one concern has always been that ours must be activated manually and that we had no way of homing in on the POB...we were simply left to wait for outside resources to initiate a rescue. When the Kannad PAB became available, we immediately became interested. This would theoretically allow us to manage the location of a POB ourselves through our AIS system. Again...we were concerned that this appeared to be manual activation only. This concern was further reinforced recently by the tragic loss of Ned Cabot off the coast of Newfoundland this Sept. As I understand it, Ned was indeed wearing a 406 PLB, but presumably was unconscious and could not activate it. After checking the Kannad site again http://www.kannadmarine.com/en/safelink-r10 I discovered that the new ones have an option for "semi-automatic" activation. Apparently, the PAB can be fitted professionally to one of a number (there is a list on their site) of auto inflation PFD/Harness ' so that when the PFD inflates automatically the PAB is activated. This is very interesting to us. I will be contacting our emergency gear supplier which is Liferaft & Survival Euipment in Portsmouth RI, USA to look into this further.
By dcaukill - 6 Nov 2012

We have the Raymarine Life Tag proximity system and the Kannad AIS system. I view them as complementary rather than either/or.

Recognise issue about false alarms on Life Tags. One have two aerials one aft and one forward and have eliminated most false alarms. Battery life is an issue but otherwise they seem Ok.acid test is to walk off the boat with one and see if it works. I have one for each crew member.we do have an agreed routine if it goes off accidentally, so it is not a real hardship.

The life tag system is reasonably inexpensive compared withe the AIS version. The latter is Circa £400 for each unit from memory. We have three, one for each person on watch.

Both require the chart plotter to be fired up to get maximum advantage. But they do different things. The life tag needs no casualty action but it only tells the boat where you went Overboard. The AIS requires me to activate it and to make sure it is above the water but if i do it tells the boat where i actually am! So I have to be conscious for it to be useful.

So I think both is good. If I fall over having hit my head - hopefully the crew will respond to the Lifetag. If I am conscious, then they will find me faster.
By dcaukill - 6 Nov 2012

I should have said: EPIRB based kit is all well and good but it doesn 't talk to the people most able to find you - your crew. No point in waking up MRCC if there is someone nearby to pick you up. Waste of time for ocean passage making, IMHO.
By DariaBlackwell - 16 Nov 2012

Here 's another article about the SPOT like devices. There are issues.

By jgbailey - 14 Nov 2013

I have frequently sail single handed so the choice for me was the PLB which is attached to my life jacket.

The bad news is that unless the weather is poor or I am on deck at night my life jacket not worn. But that is another story.

I understand from tests done in various magazines that the small AIS systems have a very limited range due to the aerial being so low down in the water. But for a crewed yacht this seems to be the route to go down.

SY Avista

John Bailey
By DariaBlackwell - 27 Nov 2013

Here 's the newest tiniest PLB yet. The rescueME PLB1 from Ocean Signal has amazing 7 year battery life and weighs only 4 ounces.


Can a PLB replace an EPIRB these days?
By jgbailey - 27 Nov 2013

Daria, suggest a PLB be it AIS / EPRIB is an individuals MOB piece of safety equipment. Hence the size etc.

An EPRIB is for the vessel and has many more ways of being stored, launched and activated. The PLB is a way of enhancing your overall safety package and should complement what you have especially if you sail with crew and have AIS on board.

It 's all about budget, the risks you are prepared to accept and the type of sailing you undertake. Husband and wife teams would clearly benefit from AIS PLB during night watch.
By alshaheen - 27 Nov 2013

Agree entirely with the last posting. The PLB and EPIRB are complementary not mutually exclusive.

However, a PLB in a MOB situation is useless unless it actuates to warn those still aboard the boat because by the time the signal reaches any rescue athorities you will have died from exposure.

Think about it. With a two man crew if one goes MOB while the other is sleeping below the sleeping partner will never know until too late unless the PLB can actuate a strong audible signal on board.
By DariaBlackwell - 27 Nov 2013

Couldn 't agree more, John. That 's why our first rule of sailing for all newbies onboard is... #1 STAY ON THE BOAT.
By DariaBlackwell - 27 Nov 2013

You 're right. I have always reckoned that if I went overboard when Alex was asleep, there is no way he could wake up, get topsides, and turn Aleria around in time to save me. Same for him. Perhaps the AIS PLB is an answer. But I 'd rather not find out. Short tether is the #1 defense.