Signal Mirrors

Some people were discussing their experiences with long distance signaling using mirrors, over on the Mt. San Jacinto Outdoor Recreation forum.  Norm5710 reported signaling 31 miles from Mt. Wilson to the west end of the San Fernando Valley.  That reminded me of playing with mirrors and something called a heliograph as a kid.  Our heliograph was pretty crude and I no longer recall where it came from – end of that story.

Nonetheless, a signal mirror is an item the armed forces recommend for a survival kit.  Signal mirrors are widely available and often priced in the $10 to $20 range.  These mirrors have a hole in the middle that you can sight through so that the sunlight is reflected at your desired target.  Using them is simple and they normally come with instructions.

While a signal mirror can be used to send morse code, that’s usually not necessary in a survival situation.  If you can see a rescuer, a car or airplane, you can aim the reflected light at them to get their attention.  If not,  you may need to flash the light across the horizon in an attempt to get someone’s attention. You can target an airplane even if you can’t see the plane.  Just aim at or ahead of the sound you hear.  The reflected light is not a laser and will flash over a pretty broad area at long distances.  The diagram above shows how to aim with a signal mirror.  It comes from the U.S. Marine Corps Summer Survival Course Manual.  The manual is available for free to our Discover Club members.

If you don’t happen to have a signal mirror with you, don’t despair.  Any reflective material can be used.  A can lid, a space blanket, a watch crystal, a belt buckle, your knife or whatever you can find.  These items may not be as accurate or as bright as a miror, but the idea is to get someone’s attention and they can be sufficient for that.

Ever tried signaling with a mirror?  What was your experience?