Signaling
Signal SOS with light, sound, or ground marks
SOS is the most universally recognized distress signal — three short, three long, three short — with any signaling method.
Step-by-step
Light or sound: three short bursts, three long bursts, three short bursts, pause, repeat.
With a whistle: three quick chirps, three 2-second blasts, three quick chirps.
With a flashlight or mirror: three short flashes, three long flashes, three short flashes toward the observer.
On the ground: stamp or scrape 'SOS' in letters at least 10 feet tall in snow, sand, or a clearing.
Keep repeating in cycles with a pause between; a single SOS is easy to miss.
Tip: The pattern matters more than the medium. A rescuer who hears three-three-three anything will investigate.
Related outdoor skills
Educational reference only. Wilderness conditions change fast — practice in low-stakes settings, take a certified wilderness first-aid course, and confirm regional regulations before you rely on any of these skills in the field.