A signal mirror is one of the most effective, lightweight survival tools, capable of flashing sunlight to rescuers or aircraft over distances of up to 40 miles. Its primary use is catching the eye of search and rescue teams when visual contact is otherwise impossible. [1, 2, 3]

 

How to Aim a Signal Mirror

Because a narrow beam of sunlight is difficult to aim accurately by eye alone, purpose-built mirrors feature a central sighting hole (or 'fireball' aiming grid). [1, 2]

 

1. Look through the hole: Hold the mirror close to your eye and look through the central sighting hole directly at your target (e.g., an aircraft or the distant horizon). [1]
2. Locate the bright spot: While looking through the hole, adjust the mirror until the bright, reflected light lands on your outstretched hand or a nearby object. [1, 2]
3. Align: Move the mirror so the glowing spot aligns with the hole you are looking through. Once the light passes through the hole, it is aimed perfectly at your target. [1, 2]

 

 

Tips for Maximum Visibility

 

• Sweep the horizon: If you do not have a clear target or are signalling a moving aircraft, slowly sweep the beam of light back and forth across the horizon or the sky. This ensures the pilot catches at least one flash. [1, 2, 3]
• Alternative method (if your mirror lacks a hole): Form a "V" with your pointer and middle fingers and frame the target (the aircraft) in that "V". Reflect the light onto your fingers and sweep the mirror so the flash passes through the "V" to cover the target area. [1, 2]
• Universal Distress Signal: The universal SOS distress signal is three quick flashes, a pause, three long flashes, a pause, and three quick flashes.
• Improvisation: In an emergency, almost any reflective, flat surface will work, including CD discs, credit card holograms, or the polished bottom of a metal tin. [1, 2, 3, 4]