Like all other survival techniques, signaling for help is a skill you should practice before you actually have to use it. If you ever find yourself lost, signaling for rescue is an option you should consider.
If you do not carry a two way communication radio, cellular phone or a whistle, you mainly will have to use visual signals. Depending on your situation and the material you have available, you can use either fire and smoke, a signal mirror, flares and flashlights or strobe lights to create your visual distress signals.
For best results when signaling for help, select a signal site close to your shelter with good visibility such as a clearing, hilltop or a lakeshore. Will there be a search for you? Put yourself in the searchers place. Will they be searching for you from the air or the ground? A search will probably start from your last known location and sweep over your proposed route.
SOS (Save Our Souls) is the best known international distress signal. Everyone should be familiar with SOS. The SOS signal can be transmitted by any method, visual or audio. The code for SOS is 3 short, 3 long and 3 short signals. Pause. Repeat the signal.
The SOS signal can, for instance, be constructed as a ground to air signal with rocks and logs, or whatever material you have available. At night you can use a flashlight or a strobe light to send an SOS to, for instance, an aircraft. During the day, you can use a signal mirror. If it is difficult to produce long and short signals, you should know that almost any signal repeated three times will serve as a distress signal. Use your imagination.
When signaling for help, the most noticeable signal is your fire. It is easily seen at night. During the day, the smoke from your fire can be seen for many miles. Build three fires in a triangle or in a straight line, with about 100 feet (30 m) between the fires. Three fires are an internationally recognized distress signal.
On a sunny day, a mirror can be a good signaling device. Any shiny object will serve – polish your canteen cup, glasses, your belt buckle or a similar object that will reflect the sun’s rays. Check your survival kit, or maybe you have a mirror sighting compass?
A flash can be seen at a great distance. Sweep the horizon during the day. If a plane approaches, don’t direct the beam in the aircraft’s cockpit for more than a few seconds as it may blind the pilot. Use the code for SOS.
Use your signal mirror properly when signaling for help. Determine where your signal is going, use your free hand as a sight line, in order for it to be effective, readjust it as you or the sun move around the sky.