Surface signalling mirror

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Maybe this is not the best place for this digression, but maybe it is. I've often carried one of those mylar emergency blankets as a signaling device. I've never tested it, but it seems to me that stretched out it will float pretty well and be pretty noticeable from the air and would present a very good radar image. Is this viable or am I wasting my time and carrying something needlessly?
 
Look at these. http://www.seerescue.com/
Mylar blankets could be used as an improvised signal, buit would need to be at least 6 feet out of the water to show up on radar. Of course when the Coast Guard looks for persons in the water they look for visual signals not radar blips.
 
ItsBruce:
Maybe this is not the best place for this digression, but maybe it is. I've often carried one of those mylar emergency blankets as a signaling device. I've never tested it, but it seems to me that stretched out it will float pretty well and be pretty noticeable from the air and would present a very good radar image. Is this viable or am I wasting my time and carrying something needlessly?

To digress even further...

I assume you are talking about one of those pocket-sized mylar sheets. If you are, inspect it periodically.

When I was on Alpine SAR, we were told that the foil coating will fuse together over time, and you'll end up with a clear piece of plastic. Not a good discovery if you're depending on it to save your life!
 
Boogie711:
Probably "not."

There's a link floating around here showing relative reflectivity of a proper signal mirror versus another commonly believed substitute - a CD. People are fooling themselves and risking their life by taking a CD and thinking it works as a signal mirror. Will it work? Sure. Does it work as well as a proper signal mirror? It's less than half as effective.

And my signal mirror floats, and it cost me about $5. For a $5 bill, I'd sure hate to see the Coast Guard plane fly overhead and disappear into the horizon. I doubt very much I'd say "Well hey, at least I saved $5."

Get a proper signal mirror - that's my advice, anyway.

I am *so* happy I blundered across this thread. I believed the CD myth. Got a link?

R..
 
Just bought two, count them two, real signal mirrors. One for me and one for my dive buddy (a product of my Grow Your Own Dive Buddy program). That then induced me to upgrade safety sausages. Now lets hope we never need either.
 
ItsBruce:
Just bought two, count them two, real signal mirrors. One for me and one for my dive buddy (a product of my Grow Your Own Dive Buddy program). That then induced me to upgrade safety sausages. Now lets hope we never need either.

Here's a tip...tie your mirror on the Sausage clip and roll it into the sausage. Its always there where you can get to it, you cant loose it trying to fumble it out of a pocket, its one complete signaling package and the sausage will help protect it...
 
Diver0001:
I am *so* happy I blundered across this thread. I believed the CD myth. Got a link?

R..

Short extract from:

http://www.equipped.com/signal.htm

The signal mirror is the most basic and best all-around signaling device. Compact and simple to operate, it has been successfully used for many rescues. While any shiny object can and has been used for signaling (see illustration for how to do so and click for larger image), a purpose made signal mirror is generally brighter and the best are much easier to aim.

In normal sunlight, the flash from a good signal mirror can easily be seen for 10 miles and generally the flash will be visible up to 50 miles, depending upon atmospheric conditions. The record rescue from one is 105 miles, at sea. A mirror will even work on bright overcast days and with moonlight, though with much reduced range. Many experts recommend carrying two as you can then more easily signal in a 360 degree sweep with a little practice. An experienced user can signal up to 270 degrees, sometimes even a full 360 degrees if the sun is high, with a single mirror, but that is pushing it for most users. One mirror per person isn't such a bad idea.

A mirror 4 inches by 5 inches (standard United States Coast Guard size) or 3 inches by 5 inches (standard large mil-spec size) is ideal. Anything much larger gets to be unwieldy and can be difficult to use for extended periods or to aim accurately. Even the USCG size can be awkward for those with smaller hands, especially if it is made of heavy material. The smaller 2 inch by 3 inch size (standard small mil-spec size) work adequately and the convenient size is an asset. There are also a few manufacturers that make mirrors even smaller than this. Generally, the bigger the better, since brightness is partly a function of the reflective area. The other determinations of brightness is just how reflective the mirror actually is and how uniform and consistent the reflected beam is, which is determined by its design, the materials used and its condition.

NOTE: We are often asked about, or see the recommendation online and elsewhere, the use of a CD-ROM as signal mirror. It is shinny, reflects light, has a hole in the center, and thus looks somewhat like a signal mirror. Moreover, many of us have lots of useless CDs around, AOL continues to send many of more of them, thus its appeal.

In tests a CD proved to be only about 20%-25% as effective (distance and brightness at distance, judged subjectively) as a 3 x 5 mil-spec plastic signal mirror, a bit more effective, but not even 50% compared to a small 2 x 3 mil-spec plastic signal mirror. It would compare worse against higher quality mirrors.
From an operational persepctive, in an After-Action Report of a major SAREX (Search and Rescue Training Exercise) conducted in 2001 by the Colorado Wing of the Civil Air Patrol, the conclusions were, "that "victims" who had never used a signal mirror (with the aiming hole in the middle) were able to use them effectively, while CD's (AOL etc.) are useless as signal mirrors."
It also has the disadvantage of requiring two hands to aim it as compared to a signal mirror with an integrated aiming device, the hole is not an aiming device. The mil-spec plastic mirrors also float, the CD may or may not, and certainly not as well. Given that a good signal mirror is not very expensive and is the most effective daytime (sunlight) signaling device, using a CD hardly seems worth the savings.
Not to say you couldn't be rescued using a CD. People have been rescued using the hologram on a credit card to signal with and the CD is far superior to that small reflective surface. A CD makes a decent improvised signal mirror compared to many other options and since they are essentially free, it may be worth carrying some for other members of your crew or party to use, multiplying your signaling capability. However, we cannot recommend a CD as a primary survival signaling device.
 
For those of us who are, shall we say, thrifty. Check the military surplus stores for signal mirrors. Usually have a few laying around and the cost is right.
 
ScubaToneDog:
Here's a tip...tie your mirror on the Sausage clip and roll it into the sausage. Its always there where you can get to it, you cant loose it trying to fumble it out of a pocket, its one complete signaling package and the sausage will help protect it...

Done. And, I tied a whistle to the whole thing. Thanks.
 
ScubaToneDog:
Here's a tip...tie your mirror on the Sausage clip and roll it into the sausage. Its always there where you can get to it, you cant loose it trying to fumble it out of a pocket, its one complete signaling package and the sausage will help protect it...
With great respect, you may want to reconsider this...

First, you'll be wanting to practice shooting a bag on nearly each dive you make, and perhaps numerous times during your practice dives. You may want to do so without having anything dangling off it. Moreover, its easy to become tangled in your SMB or the line attached to it while shooting the bag. It takes quite a bit of practice to be proficient. Your chances of tangling up are only increased by having something dangling off your SMB.

Second, if you're shooting the bag from a safety stop or at depth if on a drift dive, the bag will be heading to the surface. Hopefully you'll end up with it, but there are few guarantees.

A good place to carry a signal mirror is tucked in the back flap of your wetnotes, in your pocket. It'll be there when you need it, and not somewhere else. Tie a small SS boltsnap onto the grommet in the corner. Its easy to drop the thing if after you've been floating for a few hours. Snap it to the bungee on your secondary second stage, or another attachment point to ensure you can deploy it quickly but won't drop it.

Whatever works best for you, but you may want to pull out your SMB from time to time without having a signal mirror dangling from it.

FWIW. YMMV.
 

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