Singlehanded: EPIRB or PLB?

[Neeves]

Not sure about the comments about doubts of detection with PLB against Ebirb, don’t both use the same signal and satellite and trigger to your home state coastguard? And both give location with epirb being longer battery which is obvious as it’s a bigger size. Not sure who would trigger your epirb though if you went overboard single handed

The same [person who would throw you a life buoy - which are mandatory (in some places) - even if you are single handed


Interesting query of the detection range of a PLB vs EPIRB - worthy of a learned comment. If they have the same range - why carry an EPIRB - apart from its longer battery life?

DSC VHF - I've never heard one, are they used, is it common?

Jonathan

 

[Daverw]

Epirb obviously auto transmits on setting free from holder hench most likely to be activated by sinking or deliberate launch. Not sure if I would remember to grab as I went overboard but PLB always at hand on LJ, also Epirib floats whilst PLB doesn’t unless in floatation pouch. I think for a fully crewed boat epirb for whole crew/Boat safety and AIS beacons for each crew

 

[Neeves]

Epirb obviously auto transmits on setting free from holder hench most likely to be activated by sinking or deliberate launch. Not sure if I would remember to grab as I went overboard but PLB always at hand on LJ, also Epirib floats whilst PLB doesn’t unless in floatation pouch. I think for a fully crewed boat epirb for whole crew/Boat safety and AIS beacons for each crew

Hopefully if you are wearing the PLB when you become a statistic you will keep the PLB afloat

Jonathan

 

[Neeves]

My understanding, which may be flawed, is there are a number of types of PLB.

Some PLBs work on the 121 frequency and their signals can be picked up by aircraft or other vessels (with the compatible equipment - which most aircraft and large commercial vessels will have). These PLBs are like small EPIRBs. Set one, or either off and you should have international rescue organisation looking for you fairly quickly. If you are crossing the Atlantic and become an MOB - jolly useful. But it might be a bit slow in arriving and if the water is cold - they might not be quick enough.

The other PLBs work more locally and are reliant on VHF transmission and receiver, a dedicated device on the yacht from which you fall or through AIS, other vessels in the vicinity. To be useful for a MOB you thus need to be in waters with nearby ships, within VHF range and if this is the case these vessels (including the yacht you fell off) can home in on you and pick you up quickly (I think that is the theory). Useful if you are on a crewed yacht, or in areas with a lot of shipping or close to a 'rescue' station on land.

Possibly you can source PLBs that use both systems.

The OP mentioned cost and I might guess the VHF version might be cheaper than the 121 version - but I might be wrong.

Now ..... my understanding might be very wrong - and I'd value being corrected.

Jonathan

 

[requiem]

In Australia - if you venture offshore, not sure if its 3 nm or 12 nm you legally should carry an EPIRB for the vessel. PLBs are voluntary - this is indication of the value the authorities/bureaucracy place on the 2 items.

Its a simply answer - carry the EPIRB. If you go OB in the middle of the Atlantic who will react to your PLB, if detected how long will it last and how long will you last in the water - with the yacht powering ahead on AP.

More likely that requirement is because an EPIRB is considered "for the boat" rather than "for the person", and so the expectation is that equiping a boat with a smaller one wouldn't be justified. Speaking of AP, you might want to have a remote keyfob to control it if going solo. Not sure the range on those, but since one boat I'm playing with has one so I can test it at some point. (Also useful if you need to go into the rigging or to the bow for coral-head dodging.)

Interesting query of the detection range of a PLB vs EPIRB - worthy of a learned comment. If they have the same range - why carry an EPIRB - apart from its longer battery life?

DSC VHF - I've never heard one, are they used, is it common?

Detection range is pretty much equivalent; apart from the battery (and thus the size) there's little difference; they talk to the exact same set of satellites. An EPIRB is also designed to float and transmit, so you have have it on a tether floating outside a liferaft. With a PLB you'll need to figure out some way to attach it (e.g. to the front of your inflated lifejacket), if you don't want to be holding it in your hand the whole time.

Regarding DSC, my understanding is that pretty much any fixed VHF manufactured in the past two decades is required to support DSC. (It's still rare on handhelds.) But that's just a digital mode for your radio; perhaps slightly better range/penetration than voice.

My understanding, which may be flawed, is there are a number of types of PLB.

Ah, this looks like an issue of terminology. Properly speaking, only the 406 MHz distress beacons are true PLBs. Other devices are satellite messengers (e.g. inReach), AIS MOB devices (e.g. Ocean Signal's MOB1), SARTs, etc. Satellites no longer monitor the 121 MHz frequency, but many PLBs and EPIRBs also transmit a low power 121 MHz signal with the idea that it can used to home in on the device once a searcher is in range. (Better equipped searchers will simply home on the 406 MHz signal which can be detected more reliably and tracked from much further out.)

 

[Neeves]

More likely that requirement is because an EPIRB is considered "for the boat" rather than "for the person", and so the expectation is that equiping a boat with a smaller one wouldn't be justified. Speaking of AP, you might want to have a remote keyfob to control it if going solo. Not sure the range on those, but since one boat I'm playing with has one so I can test it at some point. (Also useful if you need to go into the rigging or to the bow for coral-head dodging.)



Detection range is pretty much equivalent; apart from the battery (and thus the size) there's little difference; they talk to the exact same set of satellites. An EPIRB is also designed to float and transmit, so you have have it on a tether floating outside a liferaft. With a PLB you'll need to figure out some way to attach it (e.g. to the front of your inflated lifejacket), if you don't want to be holding it in your hand the whole time.

Regarding DSC, my understanding is that pretty much any fixed VHF manufactured in the past two decades is required to support DSC. (It's still rare on handhelds.) But that's just a digital mode for your radio; perhaps slightly better range/penetration than voice.



Ah, this looks like an issue of terminology. Properly speaking, only the 406 MHz distress beacons are true PLBs. Other devices are satellite messengers (e.g. inReach), AIS MOB devices (e.g. Ocean Signal's MOB1), SARTs, etc. Satellites no longer monitor the 121 MHz frequency, but many PLBs and EPIRBs also transmit a low power 121 MHz signal with the idea that it can used to home in on the device once a searcher is in range. (Better equipped searchers will simply home on the 406 MHz signal which can be detected more reliably and tracked from much further out.)

Thanks Requiem

Its a topic that needs clear definitions - or we talk at cross purposes.

How do the 406 PLB talk to the boat - the optimum is the parent boat picks up the MOB - because it should be quick, or quicker, than relying on an international effort.

Jonathan





Jonathan

 

[requiem]

How do the 406 PLB talk to the boat - the optimum is the parent boat picks up the MOB - because it should be quick, or quicker, than relying on an international effort.

They don't, unfortunately. I don't know of any hybrid beacons that can use both Cospas-Sarsat and AIS/DSC. I suspect the certification requirements may largely preclude such a device . It's a topic that occasionally pops up: should one carry a PLB or an AIS beacon, if you only have funds for one? The latter are much more useful when your boat still has capable crew aboard, or when many others close by have AIS capability. The PLB is more useful when there's nobody close at hand.

 

[Neeves]

They don't, unfortunately. I don't know of any hybrid beacons that can use both Cospas-Sarsat and AIS/DSC. I suspect the certification requirements may largely preclude such a device . It's a topic that occasionally pops up: should one carry a PLB or an AIS beacon, if you only have funds for one? The latter are much more useful when your boat still has capable crew aboard, or when many others close by have AIS capability. The PLB is more useful when there's nobody close at hand.

I think you explore the options, succinctly, that the OP raised. He does not mention where he will be sailing but does mention 'singlehanded'. If the waters are are cold and he wears a PLB 24/7 then they will recover the body.

Stay on board.

Jonathan

 

[Juan Twothree]

Thanks Requiem

Its a topic that needs clear definitions - or we talk at cross purposes.

How do the 406 PLB talk to the boat - the optimum is the parent boat picks up the MOB - because it should be quick, or quicker, than relying on an international effort.

Jonathan





Jonathan

Not sure if all PLBs work the same way, but the type carried on the lifejacket of every RNLI crew member sends the GPS location to a satellite, which then alerts the relevant desk at the CG centre at Fareham.

Additionally, the beacon transmits a homing signal on 121.5, which can be picked up by aircraft, and also all classes of lifeboat, with the exception of D Class.

 

[Neeves]

Not sure if all PLBs work the same way, but the type carried on the lifejacket of every RNLI crew member sends the GPS location to a satellite, which then alerts the relevant desk at the CG centre at Fareham.

Additionally, the beacon transmits a homing signal on 121.5, which can be picked up by aircraft, and also all classes of lifeboat, with the exception of D Class.

Here the satellite receiving the alert would signal to Maritime Safety - they would then check the details of the individual and ensure the person was where the satellite advises. If the signal was found to be genuine the nearest available resource would then be direct to proceed to the location (which might be far out in the Indian Ocean). For an RNLI member the confirmation that the signal was genuine would be almost immediate and the MOB would be within his 'local' area and the RNLI vessel would be there and already searching. , if it is a leisure yachtsman it might take time to confirm the signal was genuine - if you are 500nm out in the Atlantic further delays - so different story.

The part I'm not sure about

If the PLB is transmitting to a satellite how do people on the yacht find the MOB - they don't necessarily know when the MOB was lost, he was alone on deck - can they receive a signal of the location of the PLB/MOB. 406 is marvellous - but not much use for a short handed crew if they have no idea where to look (and even if you are 'there' a man in the sea is difficult to find (in the dark) and you really don't know if you are there - unless you find him.

There may be a simple answer - I don't keep up to date on PLB developments - it would be, more than, interesting to know.

Jonathan

 

[Supertramp]

I understand that DSC VHF means the radio carries your call sign, Mmsi number and your position so that in a distress situation you can send a mayday quickly with the distress button. It also allows rapid contact to a specific user in non emergency situations. So it complements an EPIRB and should be used first. All these systems might seem over the top but I agree with Neeves that you should avoid having to use them. But if you do, you have to know they will work and how to use them. Do you know how to operate your PLB in the dark, cold and in the water?

Its probably worth a seasonal check that the radio has the correct coding and picks up your position. And a check of operating your PLB - how many people test them each season?

 

[Iliade]

Aren't two PLBs cheaper than one EPIRB? (24 hours vs. 48 hours)

 

[Tranona]

In Australia - if you venture offshore, not sure if its 3 nm or 12 nm you legally should carry an EPIRB for the vessel. PLBs are voluntary - this is indication of the value the authorities/bureaucracy place on the 2 items.

This is a typical example of legislation that is specific to particular situations and not a good idea to think that such actions are valid elsewhere. EPIRBs are an Australian "invention" in that your environment and infrastructure means it is the most appropriate way for lost people to communicate with recue services - and the main "market" is land based rather than maritime. On the other hand densely populated Europe, and particularly northern Europe has an extensive network based on phone and radio coverage, integrates with the rescue services.

At one time details of all EPIRB activations world wide were published by state of registration and type of user (not sure if it still is). About 5 years ago I analysed the list of activations and it was clear that the biggest state was Australia, followed by USA and the biggest user type land based, followed by aviation and a long, long way behind maritime. combination of Europe and maritime resulted in tiny numbers of activation. This is supported by UK Coastguard statistics where EPIRBs barely register as a means of first alert.

This may change as more and more people buy EPIRBS and PLBs, but I suggest it will always be very small in coastal waters (up to. say 60 miles offshore) because there are simpler, more effective methods available. The research I did was prompted by the Greek authorities requiring EPIRBs on charter boats despite the fact that there had been only one recorded case of a charter boat foundering - and that was in sight of land and several other boats. The requirement had then been in place for 10 years or so, but there was no record of any activations.

This does not, of course mean that beacons don't have a value, but it is questionable in coastal waters, either PLBs or EPIRBs. While there have been a very small number of examples of people being located and saved in UK coastal waters, a rational risk assessment would not lead one to the conclusion that they are a "must have". Probability of falling overboard, or the boat foundering is close to zero - probability of being found while still alive, also close to zero. Of course these probabilities increase - particularly the "located and found" when going offshore as the alternative of radio and to an extent phone communication is lost.

 

[Lightwave395]

Appreciate the cost implications but I have an epirb for the boat and a PLB for me - I did re-read the instructions and test both before I crossed from Roscoff to Falmouth solo last year

 

[dunedin]

Here the satellite receiving the alert would signal to Maritime Safety - they would then check the details of the individual and ensure the person was where the satellite advises. If the signal was found to be genuine the nearest available resource would then be direct to proceed to the location (which might be far out in the Indian Ocean). For an RNLI member the confirmation that the signal was genuine would be almost immediate and the MOB would be within his 'local' area and the RNLI vessel would be there and already searching. , if it is a leisure yachtsman it might take time to confirm the signal was genuine - if you are 500nm out in the Atlantic further delays - so different story.

The part I'm not sure about

If the PLB is transmitting to a satellite how do people on the yacht find the MOB - they don't necessarily know when the MOB was lost, he was alone on deck - can they receive a signal of the location of the PLB/MOB. 406 is marvellous - but not much use for a short handed crew if they have no idea where to look (and even if you are 'there' a man in the sea is difficult to find (in the dark) and you really don't know if you are there - unless you find him.

There may be a simple answer - I don't keep up to date on PLB developments - it would be, more than, interesting to know.

Jonathan

Currently there are separate devices needed (certainly originally the rules prevented their being combined…..
1) PLB - which sends a distress message and position via satellite - goes to Coastguard control centre, not any other vessels
2) AIS MOB beacon - which uses AIS on VHF. Should be visible on all sufficiently modern AIS sets within VHF range, also can send a DSC message to a specific MMSI - typically set to the mother ship (but easy to enter wrong). Some are able to send all ships DSC message but apparently rules vary by region.
The AIS MOB type are most use for a fully crewed boat - and have saved lives in practice, eg ocean races.

 

[Neeves]

We are law abiding and have a registered EPIRB.

We don't have PLB or AIS MOB types. We do have, what I consider, well thought out jackstays, down each deck, from each bow diagonally to the mast, across the cockpit, (under the cockpit roof beam to beam) + hard points in locations where we would commonly work.

I don't have an EPIRB with me, its unsurprisingly - on the boat, but mention is made of testing it (or a PLB). How do you, can you actually test that it transmits?


I've just checked prices here: an EPIRB costs around Stg180, a PLB stg160 and a AIS/DSC stg200 - these are the cheapest (an EPIRB meeting Cat 1 will cost Stg 350). PLBs do not meet Australian Maritime safety requirements for vessel EPIRBs and any vessel venturing more than 2nm offshore must carry an EPIRB. To put these prices in context a manual lifejacket costs Stg 60/70 and up.

To answer one of Tranoma's comments - you don't need to travel far offshore (or away from one of our State's capital cities) in Australia and have no phone coverage and be too far from the nearest VHF repeater (and few yachts now have SSB/HF).

Jonathan

 

[Tranona]

To answer one of Tranoma's comments - you don't need to travel far offshore (or away from one of our State's capital cities) in Australia and have no phone coverage and be too far from the nearest VHF repeater (and few yachts now have SSB/HF).

Jonathan

Yes that really illustrates the point that what is appropriate for one country is not directly relevant to others.

Manufacturers (and, to use that horrible social media term, influencers) have done a good job convincing us of the necessity of these devices, mainly by "hiding" the evidence of their actual use, preferring to concentrate on the odd miraculous rescue that hits the headlines and by reference to their use in other settings, be it Australia or fishing boats rather than leisure boats.

 

[westhinder]

Have you tested the PLB battery status? I have a McMurdo PLB 4 years past battery due date which still shows near full life using test.
My approach is to definitely but a replacement PLB, but keep the old past date one as a backup.
Might be grateful if the primary one fell or failed.

That will be my approach as well. The old PLB still tests ok, so I’m not going to throw it away. But for peace of mind I will buy a new one

 

[Roberto]

They don't, unfortunately. I don't know of any hybrid beacons that can use both Cospas-Sarsat and AIS/DSC.

Hello,
there are a couple (that I know of), one is McMurdo G8M AIS beacon, operates both via Satellite and AIS
ex.
McMurdo SmartFind EPIRB Series – Seas of Solutions

 

[Vicarage]

The part I'm not sure about

If the PLB is transmitting to a satellite how do people on the yacht find the MOB - they don't necessarily know when the MOB was lost, he was alone on deck - can they receive a signal of the location of the PLB/MOB. 406 is marvellous - but not much use for a short handed crew if they have no idea where to look (and even if you are 'there' a man in the sea is difficult to find (in the dark) and you really don't know if you are there - unless you find him.

There may be a simple answer - I don't keep up to date on PLB developments - it would be, more than, interesting to know.

Jonathan

They don't, sorry. You're thinking of AIS beacons, which go off when the lifejacket inflates and then send a DSC message to boat before sharing their position using AIS. This is only a local signal and won't go to the coastguard unless you're in VHF line of sight.

We thought about this a lot on the boat I worked on, and went for AIS beacons as we have 14 crew and the important thing is that the boat can find you quickly - they can pass a mayday on to shore if needed.

I also have a 406 PLB for when I do singlehanded sailing, short handed deliveries and instructing where I wouldn't expect the boat to be able to get me.

My understanding is that the current legislative framework doesn't allow the two types of beacon to be combined into one unit, though I'm sure it will catch up at which point we will hopefully see combined beacons that do it all.