Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. Otherwise it worked great. I imagine
it might be hard for a person in a sinking boat to do this in spite of
practice so why not.........

Mount the laser in a housing with a weight so it always points toward
the horizon. The laser would also be mounted on a flexible rod that
would vibrate at the correct period when thumped by a spring loaded
hammer (a tuning fork like thing).

Parallax wrote in message
om...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. Otherwise it worked great. I imagine
it might be hard for a person in a sinking boat to do this in spite of
practice so why not.........

Mount the laser in a housing with a weight so it always points toward
the horizon. The laser would also be mounted on a flexible rod that
would vibrate at the correct period when thumped by a spring loaded
hammer (a tuning fork like thing).

I have had one of these for over two years. It does not need to be
"giggled" slowly to be noticed. It sounds to me like the person who wrote
the article may not have tested it.

The lens in the device spreads the laser out along a angle (i.e. it draws a
line). The farther away you are from the device, the longer the line is.
At 16 miles, the line is 6000 feet high. The personal ones are about the
size of a AA battery maglight. Our snowmobile club has done some testing of
them, and we have easily seen them at about 15 miles at night with the
unaided eye. If you were in the ocean and somebody looking for you with
night vision, 20+ miles would be no problem at all.

Both the military and coast guard search and rescue are officially using
them. The companies website is www.greatlandlaser.com/

Scott

Parallax wrote in message
om...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. Otherwise it worked great. I imagine
it might be hard for a person in a sinking boat to do this in spite of
practice so why not.........

Mount the laser in a housing with a weight so it always points toward
the horizon. The laser would also be mounted on a flexible rod that
would vibrate at the correct period when thumped by a spring loaded
hammer (a tuning fork like thing).

I have had one of these for over two years. It does not need to be
"giggled" slowly to be noticed. It sounds to me like the person who wrote
the article may not have tested it.

The lens in the device spreads the laser out along a angle (i.e. it draws a
line). The farther away you are from the device, the longer the line is.
At 16 miles, the line is 6000 feet high. The personal ones are about the
size of a AA battery maglight. Our snowmobile club has done some testing of
them, and we have easily seen them at about 15 miles at night with the
unaided eye. If you were in the ocean and somebody looking for you with
night vision, 20+ miles would be no problem at all.

Both the military and coast guard search and rescue are officially using
them. The companies website is www.greatlandlaser.com/

Scott

On Mon, 16 Feb 2004 20:41:34 -0900, "Scott Ruby"
wrote:


Parallax wrote in message
. com...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. ///

I have had one of these for over two years. It does not need to be
"jiggled" slowly to be noticed. It sounds to me like the person who wrote
the article may not have tested it.
///
Scott


It sounds as though Scott may not be aware of the impact of a flashing
light. Some aircraft use double flashing strobes for this purpose.
No more power, but more eye-grabbing.

Brian W

On Mon, 16 Feb 2004 20:41:34 -0900, "Scott Ruby"
wrote:


Parallax wrote in message
. com...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. ///

I have had one of these for over two years. It does not need to be
"jiggled" slowly to be noticed. It sounds to me like the person who wrote
the article may not have tested it.
///
Scott


It sounds as though Scott may not be aware of the impact of a flashing
light. Some aircraft use double flashing strobes for this purpose.
No more power, but more eye-grabbing.

Brian W

Brian Whatcott wrote wrote:


Parallax wrote in message
. com...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. ///

I have had one of these for over two years. It does not need to be
"jiggled" slowly to be noticed. It sounds to me like the person who
wrote
the article may not have tested it.
///
Scott


It sounds as though Scott may not be aware of the impact of a flashing
light. Some aircraft use double flashing strobes for this purpose.
No more power, but more eye-grabbing.

It also sounds like you might not be aware of the huge difference in the
quality of light the laser flare gives out. Much more eye-grabbing than a
stobe or other light source.

One of the tests they did was to see if a observer in a plane could pick it
out from other lights at an airport at night. They had no problem
identifiying it from various locations. They did the same test from variouls
spots in the middle of a city. Also no problem.

Scott

Brian Whatcott wrote wrote:


Parallax wrote in message
. com...
Practical Sailor had an interesting article about a laser device used
as an alert/locate device for ppl in distress. Basically its a 5 mW
laser diode with a plastic line generating lens. They say that it has
to be held to sweep the horizon and jiggled slowly and that it takes
practice before it is needed. ///

I have had one of these for over two years. It does not need to be
"jiggled" slowly to be noticed. It sounds to me like the person who
wrote
the article may not have tested it.
///
Scott


It sounds as though Scott may not be aware of the impact of a flashing
light. Some aircraft use double flashing strobes for this purpose.
No more power, but more eye-grabbing.

It also sounds like you might not be aware of the huge difference in the
quality of light the laser flare gives out. Much more eye-grabbing than a
stobe or other light source.

One of the tests they did was to see if a observer in a plane could pick it
out from other lights at an airport at night. They had no problem
identifiying it from various locations. They did the same test from variouls
spots in the middle of a city. Also no problem.

Scott