Another AIS vs 406 MOB thread...

[FL390]

There are a number of threads looking at AIS vs 406 MOB devices. Each has pro and cons. I was wondering if there was any expertise on this forum that can relate the theory of these devices into real world SAR application.

For example the MCA say AIS signals are not monitored but used for situational awareness. What’s the reality of a MOB AIS signal being picked up? Would assets be used to investigate?

In the case of a 406 activation, what would be the time line for rescue? Is there anything I can do to facilitate a more rapid response? Do the MCA have immediate access to the RYA SafeTrx data?

In particular if there was any specialist knowledge related to my sailing area between Eastbourne and Selsey Bill I would be most grateful. I tend to sail mid week singlehanded so not many boats around. I am coming to the conclusion that I’d be waiting a while for a 406 rescue, AIS would be relying on luck and perhaps just a good waterproof handheld VHF might be equally beneficial.

Many of the articles I read don‘t really touch on the detail of what happens behind the scene, or if they do the authorities are understandably limited to the official line.

 

[dunedin]

I always assumed that an AIS based MOB device (like the MOB1 AIS fitted to our life jackets) are intended for crewed yachts, such that the people left on board can go back and find the MOB. Lives have been saved due to this, notably one in a round the world race.
If singlehanded I carry a GPS PLB beacon and a VHF. Although the chandlery who sold me the PLB cheerfully told me that, in cold U.K. waters, it helps the lifeboat find the body ;-)

 

[dunedin]

Re RYA SafeTrx there is a lot of confusion about this. It basically has two very separate parts
1) the static data with boat details, contact details etc (replacing the old CG66 form) - this is entered once before use, submitted to a central shore based database, and is accessible by MCA at any time
2) use of the mobile application for a voyage- as far as I know this needs a mobile signal, so is very restricted in its applicability- recently been said to be mainly aimed at very small boats close to shore. I don’t know how often this is transmitted to the central database, but not to be relied upon in that respect

 

[duncan99210]

AIS MOB: short range VHF signal which may be picked up by the Coastguard or nearby vessels, who could then relay the information to the coastguard. Any such relay or direct alert would result in SAR assets being tasked. Once SAR assets are in the area, the AIS signal would be what they’d use to home in on.
406 PLB: satellite beacon, which would take up to 45 minutes for stat to reach the Coastguard. They’d then probably task SAR assets at the same time as carrying out a check with nominated persons ashore to confirm its likely to be a genuine alert. I think that PLBs also transmit a second signal which can be picked up by SAR assets: certainly used to be the case but not sure if its still built into modern beacons.
I carry both beacons: AIS to help the Admiral find me if I go overboard, PLB so that I can alert the wider world as to where I am should the Admiral fail to find me.
I don’t bother with a handheld VHF as I’ve already got enough kit clipped to my lifejacket....

 

[Tintin]

Ais mob is not designed as an "alerting" device, but as a "finding" device. It has very short range.

As such, 406 PLB is the way to go if solo.

 

[Tintin]

Do you always clip on when going forward and in cockpit if reefed? Are your jackstays central, and your tethers short enough to prevent you going over the side?

It's far far better to concentrate on staying on board and have suitable safety procedures that you especially adhere to when solo, IMHO.

Oh and get a 406 PLB.

 

[lustyd]

Although the chandlery who sold me the PLB cheerfully told me that, in cold U.K. waters, it helps the lifeboat find the body ;-)

they should tell that to the chap fished out of the Irish Sea alive and well after falling out of his Rib a few years ago.

 

[[3889]]

My UK registered PLB self-actuated due to water ingress whilst in a Spanish harbour. Three hours later my ex (slightly embarrassing early on a Sunday morning - she was still my shore contact) phoned to tell me the Spanish coast guard had rung her to inquire as to my whereabouts. Personally I think this is a reasonable response time though far from instant. I do wonder if things would have happened more quickly if my position had been reported as mid-Biscay.

PLB recommendations

 

[matt1]

I carry 406 EPIRB when solo. I wouldn't rely on AIS alone. Range of an AIS at sea level wouldn't be great.

The standards are changing (in the US at least) and I think I am right in saying you can only sell EPIRB's in the US in if they are combined with an AIS. Seems like a good way to go as you can use the AIS for accurate pin pointing. The US rationale is apparently with AIS included, they expect the vast majority of "rescues" to be undertaken by vessels local to the casualty therefore saving the coastguard having to respond to every EPIRB activation.

There's a couple of combined AIS / EPIRB's on the market now (I think around £570)

 

[Gary Fox]

My UK registered PLB self-actuated due to water ingress whilst in a Spanish harbour. Three hours later my ex (slightly embarrassing early on a Sunday morning - she was still my shore contact) phoned to tell me the Spanish coast guard had rung her to inquire as to my whereabouts. Personally I think this is a reasonable response time though far from instant. I do wonder if things would have happened more quickly if my position had been reported as mid-Biscay.

PLB recommendations

I didn't know that is even possible, a PLB 'self-activating'. Looking at your photo, I am a bit shocked! I'm another who wears one on my l-j belt. Obviously it gets wet and salty .
Now thinking about an extra layer of waterproofing, like one of those zip lock bags, rather than relying on the casing of the PLB.
I wonder if you contacted the maker, and if it was design fault? How could a repetition be avoided?

 

[Strikeliner]

Gary Fox is exactly right. PLB's are NOT water activated. EPIRBS yes but NOT PLB's (Lot's of CAPs here!)
BUT (oh there's more) Personal AIS for local search by crew/other boats and PLB for wide area search by SAR assets. If you sail single handed don't rely on personal AIS. Go for a PLB and remember you have to switch it on yourself

 

[[3889]]

Gary Fox is exactly right. PLB's are NOT water activated.

Mine was, though not by design

 

[dk]

Yep, worth remembering that a PLB will not auto-activate on immersion, whereas an EPIRB or AIS MOB beacon will. So a PLB is not much use if you're solo and have been knocked unconscious by the boom before being pushed overboard!

 

[FL390]

The automatic activation of the AIS is one of the attractions for me. If I was in the Solent I would probably opt for the AIS unit, being aware it is not a beacon. Although I only really sail a couple of miles of the coast it is in a much quieter area, as such I am not confident I would ping up on someones AIS. I note the local National Coast Watch (NCI) operate a AIS watch. I have emailed to ask exactly what their capabilities are.

 

[Strikeliner]

Just a little follow up on DK's post re beacon activation on immersion.
The MOB1 personal |AIS activates if correctly fitted to a lifejacket when the jacket inflates (on Immersion of course). There will be instances where the beacon has been fitted incorrectly or has become compromised during jacket wear. In these cases the beacon may not activate automatically. So make sure know how to how to activate manually i.e. yourself.
This goes for all beacons. Make sure you know how to use them. How many people left on board the vessel that the MoB has fallen off will know what to look for and how to locate the casualty? What else should they do? I.E call a mayday. How would they get you back on board?
If you have fallen off the vessel and been knocked unconscious good luck! Those left on board should definitely call a mayday 'cos in most cases they won't get you back on board.

 

[Sharky34]

There are a number of threads looking at AIS vs 406 MOB devices. Each has pro and cons. I was wondering if there was any expertise on this forum that can relate the theory of these devices into real world SAR application.

For example the MCA say AIS signals are not monitored but used for situational awareness. What’s the reality of a MOB AIS signal being picked up? Would assets be used to investigate?

In the case of a 406 activation, what would be the time line for rescue? Is there anything I can do to facilitate a more rapid response? Do the MCA have immediate access to the RYA SafeTrx data?

In particular if there was any specialist knowledge related to my sailing area between Eastbourne and Selsey Bill I would be most grateful. I tend to sail mid week singlehanded so not many boats around. I am coming to the conclusion that I’d be waiting a while for a 406 rescue, AIS would be relying on luck and perhaps just a good waterproof handheld VHF might be equally beneficial.

Many of the articles I read don‘t really touch on the detail of what happens behind the scene, or if they do the authorities are understandably limited to the official line.

Presumably AIS MOB devices are limited to any VHF range, whereas 406 aint.

 

[dk]

Presumably AIS MOB devices are limited to any VHF range, whereas 406 aint.

Correct, although at just above sea level the AIS beacon's range is reduced to more like 3-4nm.

 

[prv]

a PLB is not much use if you're solo and have been knocked unconscious by the boom before being pushed overboard!

Frankly I don't expect anyone to come back alive from that whatever type of beacon they use.

Pete

 

[zoidberg]

Vendee Globe skipper Kevin Escoffier is in a liferaft tonight, 600nm SW of Cape Town, with 4 other boats searching for him in the dark. Reportedly, he has and used an 'AIS beacon' device which is low-powered and is being blanketed by the seas.

Jean Le Cam found him at dusk, then lost sight of him while manoeuvring.....

Part of the answer to 'which beacon' might emerge from this.

 

[Gary Fox]

Vendee Globe skipper Kevin Escoffier is in a liferaft tonight, 600nm SW of Cape Town, with 4 other boats searching for him in the dark. Reportedly, he has and used an 'AIS beacon' device which is low-powered and is being blanketed by the seas.

Jean Le Cam found him at dusk, then lost sight of him while manoeuvring.....

Part of the answer to 'which beacon' might emerge from this.

Well a quick look at the news says it is being coordinated by CROSS Gris Nez and the race organisers, he must have got off an EPIRB successfully.
A mickey-mouse AIS gadget may not last long anyway.
Let's pray he has a good supply of proper red parachute flares, to fire at intervals during the hours of darkness.
Fingers crossed.