AIS Beacons and laser flares

[KAM]

I have not replaced any flares for many years now and was thinking of going flare less this year. I currently have a PLB, fixed DSC VHF, Submersible portable VHF and an AIS receiver hooked up to a plotter. I was thinking of getting an AIS beacon principally for crew MOB but how good would an AIS beacon be as a general distress tool for instance would it be any use if I went overboard single handed. I thought I read a post somewhere that big ships may not monitor class B transmissions at all. Second point has anyone used one of these. Is it practicable to deploy and keep the ariel clear of the water whilst in a rough sea. (Likewise for a small PLB or hand held VHF). I was also thinking of getting some sort of laser device for attracting attention from shore or other small vessels not equipped with VHF etc. Is there any international standard for the signal from a distress laser other than random flashes or would it be better to have one of the new generation ultra bright torches which flash SOS. Do helicopters still need a smoke signal to judge wind for a winch rescue. Presumably if they did they would drop their own.

 

[prv]

AIS SARTs are intended to help a crewed boat return to someone who has fallen off it. I think they're excellent for that but I wouldn't plan to rely on them for any other purpose. The range is limited (Kannad state 4 miles for theirs), and most boats' equipment will not set off an alert even if they do receive it - either because they don't have AIS at all, or because their kit doesn't handle SART messages specially (many don't) so you will just look like another boat.

If you go overboard singlehanded, you want a PLB, no question.

There is no standard for laser "flares" currently, and major question marks over whether someone who saw it would recognise it as a distress signal.

There's a reasonable argument that electronics have superseded rocket flares for longer-range signalling (though I'm keeping mine) but I think hand flares are still necessary for "last mile" and inshore. Jimmy Green have them for £8.40 each with a four-year life, so cost shouldn't be an issue.

Pete

 

[ShinyShoe]

If you go overboard singlehanded, you want a PLB, no question.

Completely agree. And he already has a PLB so provided he carries it and wears a lifejacket so he floats enough to deploy it he is hopefully going to be OK.

If I was thinking of somethign else it would be to upgrade the handheld VHF to a handheld DSC. Just because that will ping on people's radios and you get the reassurance that someone has heard your plight. In reality I suspect I'd wait till mine breaks and then replace with DSC!

There is no standard for laser "flares" currently, and major question marks over whether someone who saw it would recognise it as a distress signal.

There's a reasonable argument that electronics have superseded rocket flares for longer-range signalling (though I'm keeping mine) but I think hand flares are still necessary for "last mile" and inshore. Jimmy Green have them for £8.40 each with a four-year life, so cost shouldn't be an issue.

And it very much depends if you think last mile / inshore signalling is a means of signalling distress. If you are imagining being stood on the deck of your boat with a red burning ball on a stick hoping someone ashore has seen it and knows to dial 999 then you may well need to stick to pyros. On the other hand if you are imagining that your tech has brought the helo to the area and the just need to find you then you just need some means to signal to the helo where you are probably fine with a laser as it'll attract their attention. I'm sure same applies if a lifeboat or anyone else who is looking for you has a red or green light flashed across them they'll take a second look. In these cases you are looking at the Gretland Flares (cheaper!!). The Odeo is designed to be more like a handheld pyro but I'd want to see one before buying as very very pricey (although don't expire and 'burn' for hours). I do have some concerns that the public wouldn't notice it...

I'd also think smoke still has some use...

 

[KAM]

Do you think a laser flare would be any better than one of the latest ultra bright torches flashing SOS. At least there is no ambiguity about SOS and the aim would not need to be so accurate. Has anyone actually tried to use a VHF or PLB when in the water. What effect does a very wet aerial have on the range not sure I could hold it out of the water for long. As per the AIS beacon recommendation I was reading.

 

[KAM]

I would not want to rely on one device. Has anyone seen any reliability figures quoted for PLBs. How would an ultra bright 1000 lumens torch compare with a laser in daylight given that there would be much less requirement to aim the torch accurately.

 

[ShinyShoe]

Do you think a laser flare would be any better than one of the latest ultra bright torches flashing SOS. At least there is no ambiguity about SOS and the aim would not need to be so accurate. Has anyone actually tried to use a VHF or PLB when in the water. What effect does a very wet aerial have on the range not sure I could hold it out of the water for long. As per the AIS beacon recommendation I was reading.

The general advice seems to be to lie in the water with your lifejacket inflated and the PLB in the "cleavage" of the two bladders. From what I understand the difficulty may not be the Sat Aerial being wet but trying to get a decent GPS fix.

Have used VHFs from the water for close range work no issue as long as you shake the speaker and blow the mike before transmitting. Not noticed any issues with poor transmission associated with wet aerial - mine either lives on the front of a dinghy sailing buoyancy aid or in a dinghy bilges which seem to be rather wetter than Jack Holt designed them to be!

I do think that a Gretland has a better range and distinctiveness than a 1000lumen torch. If there are more than one service searching for you there may be search lights etc in use. While these wont be sending out ... --- ... you've got to watch it long enough to realise what you are looking at and that its not just a flash from a moving rescuer's head torch etc. A red or green light are more likely to attract attention as less likely to be a rescuer's torch.

The Gretland is designed to have a thin line fanned out - so distinct from a normal torch beam. That also means they've concentrated the light into that beam. You can reflect that beam off the sea and then towards the person you are trying to signal. They see the sea go red or green and then see your signal...

There are a number of key features of the Gretland Flare - night time visibility 20miles + daytime, 3miles +, locate reflective material 1 mile away, waterproof to 80ft, minimum 5 hour life (continuous use) longer for the bigger devices.

I would not want to rely on one device. Has anyone seen any reliability figures quoted for PLBs. How would an ultra bright 1000 lumens torch compare with a laser in daylight given that there would be much less requirement to aim the torch accurately.

1000lumens torch which is genuinely 1000lumens rather than a cheap copy claiming to be will cost simillar money to a Gretland.

How are you wanting PLBs tested to quote reliability? Are you meaning how often have they been deployed in anger and failed to work? Or how often have they failed a bench test? Or some artificial test where its pulled behind a boat and may or may not get a GPS fix etc? http://www.panbo.com/archives/2008/05/epirb_failures_wheres_the_meat.html and http://www.panbo.com/archives/2004/04/personal_location_beacon_failure.html Both read as though the sat signaling part works. Float free technology has issues that don't apply to a PLB and GPS has issues that we all experience from time to time in daily life. But without GPS you will still get emergency help but a position will take longer.

 

[nigelmercier]

...In these cases you are looking at the Gretland Flares (cheaper!!)...

Gretland Flares?

 

[ShinyShoe]

Gretland Flares?

Sorry GreAt rather than gret. http://greatlandlaser.com/ --> UK Distributor: www.rescue-flares.co.uk


I believe they and the Odeo Flare (www.odeoflare.co.uk) are both under assessment by the US CoastGaurd for consideration to be proposed to SOLAS as ap;proved signals in the future.

 

[KAM]

Hi Shinyshoe

Thanks for the links the SARSAT reports make interesting reading. A bit worried about the reports of PLB failures to find position but there is no detail on the tests. The figure we should initially be looking for is ability to meet manufacturers original specification at the end of the specification battery life at extreme temperature and humidity after being subjected to 5 years on a yacht. Am I expecting too much for a piece of commercial equipment. I'll need to read into it a bit more. Sounds like its worth having a backup from a different manufacturer.

 

[ShinyShoe]

From my reading of the reports there is no concern that they fail to send a EPIRB Report which would initiate the search proceedings, but there seems to be issues with getting the GPS fix. Bear in mind thats 10 years old so 2 batteries ago at least, and as batteries are not user serviceable they can do firmware upgrades at the same time.

If I was McMurdo etc I'd be doing exactly what you say - getting the PLB back, and before replacing the battery running some tests on it.

The two cases I know of where people have used PLBs had longer delays in providing a position than I'd have expected than if the GPS fix was as good as we come to expect on our iPhones etc. I think there are a number of contributory reasons for that: 1. The position of the PLB is not ideal on a wobbly surface partially blocked from a view of the sky by the 'victim's' head. 2. The GPS is starting from a cold start which means it has no-almanac that tells it which satellite's are supposed to be where so it needs to download that from the satellites. It might be able to do that in parallel from multiple sats if it can see multiples but I suspect as it wobbles about that gets interrupted 3. It has no recent location from which to begin some 'assumptions'.

If you take your iPhone etc and start it trying to get a position it will get it fastest with a clear view of the sky, having known it was there yesterday and therefore already having this week's almanac. Try switching it on in a 300miles different location, several weeks after using it previously, while you jump about with it on a trampoline with no WiFi or mobile for it to otherwise download the almanac and it will take a bit longer to get a fix. I'm sure different GPS will have different luck but I suspect there is a very big element of luck involved.

The one thing that would make a difference would be enabling the GPS periodically but that would consume battery. If Mr McMurdo is reading he should put a waterproof micro USB port on the device, let me plug it in to power (USB is the standard for power these days) the GPS separately, run test etc and let it download the almanac daily.

 

[KAM]

Hi Shinyshoes

I think the panbo link above is referring to early models of the Mcmurdo PLB. The test report here on the current model http://www.equipped.org/McMurdoNewFastFind.htm whilst not particularly scientific or representative of real conditions is pretty complimentary about the GPS performance. Do you have any links to reports of failures to locate GPS position with this model.

 

[boomerangben]

Lasers, strobes, torches etc great at night, but not terribly effective during the day. Ok at day the mk 1 eye ball is more effective during the day than at night, but if you want to be found quickly from the surface or the air, there's not much that betters a cloud of smoke.