Laser Flares

[maxi]

I see PBO featuring a laser flare product, which is something that makes a lot of sense to me, BUT;

Who has ever seen one of these in action, who would recognise a laser beam as an emergency signal as opposed to a spoilt brat a few miles away playing with his dad's laser ?.

C'mon Sarah, how about an informative article generated with the flare manufacturers, plus nighttime photos?. A safety device can only work if everyone can recognise it as an emergency signal.

 

[snooks]

Wot you mean like this?



The pinpint of light is very bright and would make sense for an addition to a lifejacket...But as a replacement for a yacht's pyrotechnics they still have some way to go yet.

 

[Twister_Ken]

Somewhere there's a bit of video from a Scottish TV programme, shot with the aid of a lifeboat crew. Conclusion, not much good. Plus, lasers are not a recognised (officially, or unofficially) method of signalling distress, so even if it's seen, the chance of it being reported as coming from someone up to their plums in foaming briny is pretty remote.

 

[jsl]

laser beams

It seems to me that the essential requirement is a cone or finger of light which will be seen when the beam is not pointing straight at the (potential) rescuer. The voices on the video can be heard referring to a 'cone', which sounds good, but also having to direct the beam towards themselves, which sounds not-so-good. Any comments? What I'd like to have is a narrow cone which could, for example, be pointed straight upwards, waved about and perhaps flashed.

 

[Seajet]

How about a hologam projection of a giant hand in the sky, finger pointing down at the casualty ?

 

[Twister_Ken]

How about a hologam projection of a giant finger in the sky pointing down at the casualty ?

Or a speech bubble, "Help!"

 

[elton]

It seems to me that the essential requirement is a cone or finger of light which will be seen when the beam is not pointing straight at the (potential) rescuer. The voices on the video can be heard referring to a 'cone', which sounds good, but also having to direct the beam towards themselves, which sounds not-so-good. Any comments? What I'd like to have is a narrow cone which could, for example, be pointed straight upwards, waved about and perhaps flashed.

Lasers are extremely directional and comprise of a very tight and narrow beam. They can be de-focussed to a fan shaped beam, but then would offer no advantage over a torch. The term "laser" conjures up ideas of an intensely powerful beam of light, but that isn't what they are. They are bright because they are a point source, that's all.

 

[maxi]

Thanks Gents, just the sort of info that I believe is helpful to boat owners, and clearly there is some knowledge out there but on a dispersed basis.

I do believe that It would be a proactive and responsible move for PBO (or similar) to produce a summarised article so that we might be collectively informed, with data collected in an objective and balanced manner.

 

[greenalien]

Surprisingly, even a powerful laser beam is almost invisible when viewed from the side, unless it's scattered by smoke/fog - so the 'cone of light' pinpointing the source is a non-starter, unless accompanied by a big smoke generator. And if there's any wind at all, that smoke will disperse rapidly downwind...

 

[ctva]

Surprisingly, even a powerful laser beam is almost invisible when viewed from the side, unless it's scattered by smoke/fog - so the 'cone of light' pinpointing the source is a non-starter, unless accompanied by a big smoke generator. And if there's any wind at all, that smoke will disperse rapidly downwind...

...you mean like a smoke flare???

 

[Twister_Ken]

...you mean like a smoke flare???

Well, a hand-held red gives off lots of smoke. Maybe that would work?

 

[maxi77]

Lasers are extremely directional and comprise of a very tight and narrow beam. They can be de-focussed to a fan shaped beam, but then would offer no advantage over a torch. The term "laser" conjures up ideas of an intensely powerful beam of light, but that isn't what they are. They are bright because they are a point source, that's all.

They are bright because a lot of energy is concentrated in a small beam. There is enough energy in many comercial products to cause real and permanent damage to the retina. Many lasers are powerful, they are used to cut steel slabs inches thick for example, or if you want to get realy nasty the Yanks have one in a 747 that can destroy missiles a thousand miles away.

 

[elton]

They are bright because a lot of energy is concentrated in a small beam.

I believe that's what I said. But "a lot (of energy)" is relative. The narrower the beam, the greater the apparent energy.

There is enough energy in many comercial products to cause real and permanent damage to the retina. Many lasers are powerful, they are used to cut steel slabs inches thick for example, or if you want to get realy nasty the Yanks have one in a 747 that can destroy missiles a thousand miles away.

Yes, many lasers are extremely powerful, but the ones we're discussing here are decidedly feeble.

 

[TopDonkey]

How about spinning the laser fast on a 15 degree offset ?, this would keep it pinpointed, but also create a hollow cone needed to make the laser more visible

 

[VicS]

The one featured in post #2 looks pretty useless.

The one I like the look of and would like like to see in a comparison video is the ODEO FLARE

Not directional. In fact claimed to cover a hemisphere + 20°.

 

[SHUG]

Better than Nothing I suppose.
The unidirectional properties of laser light are, in this case, a serious disadvantage.
There are alternative light sources such as small Xenon lamps or LED clusters which might be a better option.
Quote " 1 ODEO laser light equals 600 flares" where is the sense in that!!!
I presume they mean that the luminous flux in a particular direction is 600 times greater but, if that direction only encompasses one degree it is in fact much worse than a flare for SAR uses.
This is the sortof technical rubbish which clouds the issue which is.....is it generally more visible than a pyrotechnic flare?. Answer...NO. Back to the drawing board.

 

[Twister_Ken]

This is the sortof technical rubbish which clouds the issue which is.....is it generally more visible than a pyrotechnic flare?. Answer...NO. Back to the drawing board.

Also, will it be recognised and reported as a distress signal? Answer, probably not.

 

[VicS]

Quote " 1 ODEO laser light equals 600 flares" where is the sense in that!!!
I presume they mean that the luminous flux in a particular direction is 600 times greater but, if that direction only encompasses one degree it is in fact much worse than a flare for SAR uses

No they mean it will burn for 600 times as long. 5 hours instead of 30 seconds.... Read the website!

It is not in one direction it is visible from all directions simultaneously and
projects over the the full hemisphere ... Read the website

these are the reasons that I like the idea of the Odeo. Until it is tested or gets official approval I cant say any more than I like the idea.

 

[RAI]

The one I like the look of and would like like to see in a comparison video is the ODEO FLARE

Thanks for the link Vic. I would dearly like to get pyrotechnics replaced.

 

[VicS]

Thanks for the link Vic. I would dearly like to get pyrotechnics replaced.

Do report back on what you think of it if you buy one.

Still no substitute for parachute rocket or an orange smoke though.
The only person I have ever known who was rescued as a result of using a pyrotechnic was spotted by a passing ship seeing his orange smoke.
( in the days before we all carried VHF )