Kingman, John (September 1919). "The Isle of Capri: An Imperial Residence and Probable Wireless Station of Ancient Rome". The National Geographic Magazine. p.224 . Retrieved 18 November 2012.

Signal mirrors have several applications with their ability to send silent signals long distances without any electronics or moving parts. The two most popular applications are: When sending signals upwards, the range is much further. The signal can go up to 10 miles (52,800 feet) in the air. Some claim that signal mirrors can transmit 100 miles away. Other Benefits Signalling must be applied in good time. Signalling too late may not provide vehicles behind with enough time to react if you are intending on slowing or stopping the car. Signalling too early can give the impression you are taking a turn sooner than the actual turn you intend, or that you are parking up, leading to confusion. If parking up, ensure you do not signal before a junction. Manoeuvre This feature creates a fireball on the mesh (an image of the sun), which is used to indicate where to point the mirror. You tilt the mirror to overlay the fireball on your target.Within a few minutes, the pilots of a jet airliner flying 35,000 feet (10,700 meters) overhead saw the glint of the rafter's mirror, and realized someone was in trouble below.

Flash the mirror in the direction of your target, tilting the mirror slightly up and down to create a flashing effect. This will help catch the attention of the rescuers and make your signal more visible.Could Cause an Accident: The light from the signal mirror could go into someone’s eyes and temporarily blind them. This could result in an accident. It is important that you stop aiming the signal mirror at planes once you have been spotted.

Keep flashing it in the direction of the target until you see a response or until you are confident that your signal has been seen. A stainless steel signal mirror is the most durable and long-lasting option. They are highly reflective and can withstand harsh conditions without breaking or scratching. However, they are heavier than plastic mirrors and can be more expensive than both glass and plastic options. Features to ConsiderWhile they prepare and equip themselves carefully for their adventures, what gives them the most protection is their own ability to analyze unexpected situations and improvise solutions. One of our docs was retiring and was planning on hiking the pacific coast trail. Our manager was trying to think of a good retirement gift and I suggested a PLB. She asked what it was. I said it was for when you fall and can’t get up in the middle of nowhere. You push a button and a helicopter comes. It sends your coordinates to a satellite which relays it the government. Sometimes it is nice to see them! Once you are sure that rescuers have spotted you and are zooming in towards you, it is crucial to stop signaling. Why? The reflected light may cause them momentary blindness and may cause more accidents. With the signal mirror in hand, hold the mirror next to your eye and face the sun. Stretch out your other hand and gradually tilt your head until you see the reflected light remains on your hand.

A plastic signal mirror is a lightweight and affordable option. While they are less reflective than glass mirrors, they are still effective and can be a great choice for those on a budget or looking to minimize weight in their survival kit. However, plastic mirrors can be easily scratched, reducing their effectiveness over time.

Mirror Signal Manoeuvre routine

Remember, timing is everything when it comes to signaling for rescue, so be sure to use your signal mirror during daylight hours and when the sun is high in the sky for maximum visibility. Maintenance and Storage While anything reflective can work as a signal mirror, improvised signal mirrors can be difficult to aim. Modern signal mirrors are made with a special retroreflector to help with aiming. Acrylic mirrors are a second to glass mirrors, with their benefits being that they are lighter, less brittle, and cheaper. They can scratch easier and are ultimately less reflective than the glass models- both can affect their performance in an emergency. A ‘real’ signal mirror is a mirror with a built-in way to precisely aim it’s reflection (from the sun), and is intended to alert others of your location.