Another alternative to hand-held distress flares?

nigelmercier

nigelmercier

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I've just bought a Military-Spec Strobe Light:
$_1.JPG

http://r.ebay.com/ImDZZq

"When it comes to saving lives, anything less than the best is not an option. Since the introduction of the MS-2000(M), it has become the main Combat Search and Rescue (C-SAR) light carried by elite military forces around the world..."

Obviously I don't need the IR filter, but when the body is extended a blue filter flips over the strobe. Does Blue mean anything for SAR?

Rate is one per second.
 
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Flashing Morse SOS would be a good start, looks like a good bit of kit, although the idea that it could be a sustitute for putting up some red parachutes, or even hand flares, is clearly ludicrous.
Why not immediately start a convention that all 'here I am, rescue me ' type strobes flash SOS? They could be arriving from China in a few weeks, at least it would get rid of the 'might be mistaken for a cardinal' arguments, which are true by the way.

Lifejacket strobes could do the same. Any objections to SOS strobes? I won't charge any royalties.
 
nigelmercier said:
That is what I'm asking about, as replacements for hand-held flares, other than laser types. Note that this is not a LED, it's the same type of strobe as a camera flash.
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As in fact are most dive strobes, at least last time I dived.
You have the same thing in a military coloured box. Secondhand.
As a means of distress alerting, it is seriously challenged by the fact that divers use the same thing for a different purpose.
As a means of showing your position, yes it is a lot more use than a flare, particularly after the first couple of minutes.
They do impact your night vision though.

These days, epirbs seem to all use LED's, but I think they are as much to alert/reassure that the damn thing is working as a location feature.

I've got one of these somewhere:
http://www.ebay.co.uk/itm/STROBE-LI...ing_LightsLanternsTorches&hash=item4d056e6299
 
nigelmercier said:
That is what I'm asking about, as replacements for hand-held flares, other than laser types. Note that this is not a LED, it's the same type of strobe as a camera flash.
Click to expand...

If someone sees a h/held red flare at sea, you can be pretty sure it'll be seen as distress signal and reported or otherwise responded to.

If they see a quick flash white, then good odds it'll be interpreted as a nav buoy, and won't be reported.

So no, not a reliable replacement.
 
Does anyone know of a supplier of white lasers
I would like one to highlight my position to ships
The strobe mentioned would not be much use for distress but if a ship saw it & thought it was a diver they might do a handbrake turn & miss the user so it must have some use
 
Daydream believer said:
Does anyone know of a supplier of white lasers
I would like one to highlight my position to ships
The strobe mentioned would not be much use for distress but if a ship saw it & thought it was a diver they might do a handbrake turn & miss the user so it must have some use
Click to expand...

It's kind of a property of lasers that they are a single colour/wavelength, so white is not going to happen!
 
Alpha22 said:
They said that about LED's about 30 years ago.....
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A laser is by definition a single frequency - it can't be anything else. Lasers are effectively very, very good tuning devices; if it isn't emitting a single frequency it isn't a laser! The only way of getting a "white"-ish laser would be to have three co-axial lasers in red, green and blue. At a distance that would probably look white, though any kind of filter could have unexpected results - up to and including the light not being visible. There would also be the problem of interference effects; laser light is coherent, so where two beam combine you get sum and difference wavelengths from interference between the different wavelengths. Not sure what the effect of that would be in practical terms; at the very least a "speckle effect" as the observer moved slightly with respect to the source.

LEDs are in fact lasers - until the light hits a phosphor that is stimulated by the laser light and re-emits the light at a variety of frequencies. The laser light is confined within the device, though. The light emitted is NOT laser light, and so is not highly collimated or coherent.

Because of their extremely narrow frequency output, lasers are exceptionally easy to filter out. You can't RELY on a laser being visible through any kind of filter - including smoked windscreens, sunglasses or even double-glazing, if the gap just happens to be such that you get destructive interference between the direct and internally reflected beams.

The only advantage of a laser beam is that because it is highly collimated and coherent, it is potentially visible at much greater ranges than a similar intensity of non-coherent light. However, because of it's extremely narrow frequency range - for practical purposes you can think of it as a single frequency - it may be filtered out by intervening things like windows or sunglasses.

A final point is that lasers intense enough to be visible at long distances are necessarily dangerous to people's sight.
 
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