What does the term 'distance estimation' refer to in navigation?

Distance estimation in navigation specifically refers to the technique of measuring the distance traveled while diving based on the number of kick cycles or fin strokes made. Divers often use a consistent swimming rhythm to estimate how far they have traveled without relying solely on a depth gauge or compass. This method helps them navigate effectively, especially in environments where visibility might be limited or when they need to return to a specific location.

Using kick cycles as a method of distance estimation allows divers to independently gauge distances underwater, complementing other navigation techniques. It emphasizes the need for divers to be aware of their propulsion efficiency and to maintain a steady pace to make their distance more predictable.

The other options, although relevant to diving safety and navigation, do not specifically pertain to the act of estimating travel distance in the same direct way that kick cycles do. Thus, the focus on kick cycles marks it as the appropriate choice.