Help signals can safe many lives in case of danger. Three major help signals are used to in case of danger. The first one is three equally stakes with an arrow on the ground to indicate direction. Three equal piles of rocks with an arrow on the ground. One of the oldest types of long-distance communication is the smoke signal. It is a type of visual communication that is used to communicate across a long distance. Smoke signals are commonly used to communicate news, warn of danger, or assemble people in a common place.