A whistle is used as a signaling device. It can be used as a signal in an emergency situation or
can be used as a sound attraction device while searching. A good quality, sturdy, loud whistle
is recommended. Metal whistles should be avoided as their use in cold, winter conditions is
problematic.
The military style signal mirror is the most basic and best all-around signaling device. Compact
and simple to operate, it has been used successfully for many rescues. This type of mirror is
required for Certification. While any shiny object can and has been successfully used for
signaling, a mirror especially designed for signaling and sighting is generally brighter and much
easier to aim.
In normal sunlight, the flash from a 2-inch by 3-inch signal mirror can be seen easily for ten
miles while the flash from a 3-inch by 5-inch mirror will be visible up to 30 miles, depending
upon atmospheric conditions. A mirror will work on bright overcast days and with moonlight,
though with much-reduced range.
The 2-inch by 3-inch size (standard, small military specification size) works adequately, and the
convenient size and weight is an asset for ground-pounders.
To use a signal mirror, reflect sunlight from the mirror onto a nearby
surface (your hand, a tree, etc.). Slowly bring the mirror to eye level and
look through the sighting hole. You will see a bright spot – called the
fireball – within the surrounding mesh. This is the aim indicator. Hold the
mirror close to your eye and slowly turn it so that the fireball is on the
target. Manipulate the mirror up and down rapidly to flash the target.
Once the target indicates your flash has been spotted and turns toward you, do not keep the
mirror on it continuously, because the flash can be blinding. Continue flashing periodically until
the target arrives and indicates you have been visually located.
At least one source of light is required. A headlamp or flashlight, with extra batteries and bulbs,
will satisfy this requirement. When working in a cave, three sources of light may be required.