EPIRB versus AIS PLB

[Spirit (of Glenans)]

When my wife sailed on the 2018 ARC, the boat was equipped with an EPIRB, as required by the rules. During the planning meetings the concensus among the crew was that the most advisable Personal Locator device would be of the AIS DSC type, namely Ocean Signal MOB 1, on the grounds that, in mid Atlantic, an MOB's best hope was to be found either by their own vessel or by one of the other boats taking part in the event. It was considered that the sattelite type would result in a recovery rather than a rescue.
The Ocean Signal device is intended to be affixed to the bladder of the LJ and be activated by its inflation. It being an Irish-crewed boat, LJs were worn at all times above deck, without question.

 

[obmij]

Even if not explicitly defined there is a general understanding of PLB, which includes transmitting on 121.5 mHz- I don't think you will find any manufacturer referring to an AIS MOB device as a PLB.

It all comes down to who you want to rescue you. If you want your own vessel to then go AIS, if you want CG/RNLI go EPIRB/PLB

Unfortunately - even on this thread there is no general understanding of what constitutes a PLB. There are numerous posts at the beginning stating a PLB MUST transmit on 406 and / or it must be a SARSAT device. Neither of the statements are true.

There is also the assumption by some posters that a PLB / EPIRB are interchangeable other than battery life & will automatically contact an MRCC. Again - this is untrue (although you may have a PLB which will do so)

Finally there is an assumption by some that PLBs are part of GMDSS / or and there is an official definition or minimum performance requirements.

So a lot of potentially dangerous misinformation and misunderstanding. If you bought the PLB in the link below & went for a swim mid Atlantic as a singlehander - chances are you would be wating a long time for rescue! You'd be better of with a baloon and a party whistle!

Sea Marshall AU9-WF

Nevertheless it is useful and widely used

You can also buy an AIS only PLB, a PLB that sends a DSC call to a nominated station, in conjunction with AIS, a PLB that transmits on both 406 & 121.5 and as in the link above 121.5 only.

I would always advise having an EPIRB with HRU for your boat - but if you also want a PLB it's essential to be sure of what you are buying. You could end up with a chocolate teapot.

 

[bedouin]

Unfortunately - even on this thread there is no general understanding of what constitutes a PLB. There are numerous posts at the beginning stating a PLB MUST transmit on 406 and / or it must be a SARSAT device. Neither of the statements are true.

There is also the assumption by some posters that a PLB / EPIRB are interchangeable other than battery life & will automatically contact an MRCC. Again - this is untrue (although you may have a PLB which will do so)

Finally there is an assumption by some that PLBs are part of GMDSS / or and there is an official definition or minimum performance requirements.

So a lot of potentially dangerous misinformation and misunderstanding. If you bought the PLB in the link below & went for a swim mid Atlantic as a singlehander - chances are you would be wating a long time for rescue! You'd be better of with a baloon and a party whistle!

Sea Marshall AU9-WF

Nevertheless it is useful and widely used

A few years ago (while quite few actually) PLBs were 121.5 (and 243) devices and anything using 406 was an EPIRB, Since then the use of PLB has been extended to include those transmitting on 406 (but with the lower requirements than what is now called an EPIRB). Even now I very much doubt if you will find anything described (by the manufacturer) as a PLB that does not include 121,

As far as I know 121 has never been part of GMDSS as it comes from the Aviation industry rather than the Marine. While satelite monitoring of 121.5 ended a decade ago I think some aircraft and many ground stations do still monitor it so if that is all you have you may still get lucky.

 

[obmij]

Here is a link to an AIS PLB with DSC functionality.

It does not transmit on either 406 or 121.5

sMRT V100

I am not trying to score points - I am simply pointing out that there is a lot of misunderstanding on this subject and that this can be a dangerous thing. A lot of the posts on this thread are (no doubt unintentionally) misleading.

 

[Graham_Wright]

Here is a link to an AIS PLB with DSC functionality.

It does not transmit on either 406 or 121.5

sMRT V100

The spec is interesting;

• 5 year battery life
• 24/7 Monitoring
• Activates automatically on inflation of lifejacket, immersion in water or manually
• Indicates GPS position in less than 45 seconds
• Updates GPS position via AIS every minute
• Tracks multiple targets simultaneously
• Individual MMSI identification
• Designed to be integrated into the SOLAS approved sMRT PFD
• Enables every vessel nearby to become a SAR asset
• Works with existing VHF DSC and AIS equipment
• 150 mile transmission range with worldwide satellite coverage
• Available in IECEx approved Zone 1 model
• Optional recertification ensures optimum performance (recommended annually)

and provokes some questions!

 

[bedouin]

Here is a link to an AIS PLB with DSC functionality.

It does not transmit on either 406 or 121.5

sMRT V100

I am not trying to score points - I am simply pointing out that there is a lot of misunderstanding on this subject and that this can be a dangerous thing. A lot of the posts on this thread are (no doubt unintentionally) misleading.

But if you read the documentation they call it a "Personal Location Device" not a PLB, A minor difference but a significant one.

 

[lw395]

The spec is interesting;

• 5 year battery life
• 24/7 Monitoring
• Activates automatically on inflation of lifejacket, immersion in water or manually
• Indicates GPS position in less than 45 seconds
• Updates GPS position via AIS every minute
• Tracks multiple targets simultaneously
• Individual MMSI identification
• Designed to be integrated into the SOLAS approved sMRT PFD
• Enables every vessel nearby to become a SAR asset
• Works with existing VHF DSC and AIS equipment
• 150 mile transmission range with worldwide satellite coverage
• Available in IECEx approved Zone 1 model
• Optional recertification ensures optimum performance (recommended annually)

and provokes some questions!

Not sure I'd want to initiate a lifeboat shout for every lifejacket inflation ?I've been near.
150 mile range is quite do-able if the receiving station is high up with good antenna and only wanting AIS/DSC data rather than voice.
For a yacht, maybe these things become an argument against having the AIS aerial low down on the pushpit?
Satellite reception of AIS is out there, I wasn't aware that there's 100% coverage 100% of the time.

 

[obmij]

But if you read the documentation they call it a "Personal Location Device" not a PLB, A minor difference but a significant one.

Bedouin, did you actually click on the link? It is described as the worlds most advanced PLB and is being sold as a PLB with the words Personal Location Beacon used prominently.

This may help

What is a Personal Locator Beacon (PLB)?

LW & Graham - It's a locating device not an alerting device, so whilst useful in certain circumstances may not be exactly what you are looking for

 

[Graham_Wright]

It's listed at £80.

sMRT V100X Man Overboard PLB alerting and tracking Personal Locator Beacon | eBay

hash=item3d8da527b6:g:4M8AAOSwODBdCyNN but there seems to be some disparity between the claimed performance.

 

[bedouin]

Bedouin, did you actually click on the link? It is described as the worlds most advanced PLB and is being sold as a PLB with the words Personal Location Beacon used prominently.

This may help

What is a Personal Locator Beacon (PLB)?

LW & Graham - It's a locating device not an alerting device, so whilst useful in certain circumstances may not be exactly what you are looking for

Yes I did - did you actually look at the documentation (Brochure and User Manual). Neither describe it as a Beacon they use the term Device. It claims to comply with an RTCM standard that covers "Maritme Survivor Locating Devices". The blurb includes the statement

An MSLD system is not intended to perform the functions of an Emergency Position Indicating Radio Beacon (EPIRB) or Personal Locator Beacon (PLB)

I know it is a small distinction but I think it is important.

 

[Graham_Wright]

So what does "

• "Tracks multiple targets simultaneously"

mean?

 

[lw395]

So what does "

• "Tracks multiple targets simultaneously"

mean?

It means the AIS system can track multiple MOBs simultaneously presumably.

Looks like the ITU may now recognise such a thing as an AIS PLB. But plain PLBs are sold to idiots who go hiking in remote areas, where AIS would be about as useful as a liferaft in the desert.

 

[Graham_Wright]

It means the AIS system can track multiple MOBs simultaneously presumably.

What system? The verb is used transitively.

The information refers to something worn on the person. Errors of description like this fill me with doubt.

This doesn't help either;-

• 150 mile transmission range with worldwide satellite coverage

 

[bedouin]

What system? The verb is used transitively.

The information refers to something worn on the person. Errors of description like this fill me with doubt.

This doesn't help either;-

• 150 mile transmission range with worldwide satellite coverage

At a rough calculation that would require a mast 3000m tall

 

[Graham_Wright]

At a rough calculation that would require a mast 3000m tall

Bit unstable on a life jacket!

 

[maby]

At a rough calculation that would require a mast 3000m tall

If you read the brochure that is downloadable from their web site, you'll see that they are quoting detection ranges "from a fixed wing aircraft".

 

[Graham_Wright]

If you read the brochure that is downloadable from their web site, you'll see that they are quoting detection ranges "from a fixed wing aircraft".

…………and worldwide satellite coverage means? GPS receiving? My quote came from their website!

The detection range has reduced from 150 to 75. Not much confidence in my mind yet.

Donwloadable brochure - I couldn't find it. This sounds like the product I am looking for.

 

[bedouin]

If you read the brochure that is downloadable from their web site, you'll see that they are quoting detection ranges "from a fixed wing aircraft".

But I am not sure how many fixed wing aircraft have AIS installed

 

[maby]

But I am not sure how many fixed wing aircraft have AIS installed

I guess that any aircraft used for maritime S&R will have an AIS receiver. But don't get me wrong - I'm rather skeptical about AIS beacons based on my experience of range for hand held VHF transceivers. My wife and I carry 406 PLBs - we may invest in AIS beacons this year.

 

[maby]

P.S. if the Iridium monthly subscription were lower, the Garmin locator would seem to be the ideal solution...