What is the term for communicating by following a line with zero visibility?

The term for communicating by following a line with zero visibility is known as touch contact. This method is essential in scenarios like cavern diving where visibility is severely compromised, making visual signaling impossible. In such environments, divers must rely on physical sensations and tactile feedback to maintain communication with their buddy or to navigate through passages.

Touch contact involves techniques such as holding onto a guideline or using hand signals that can be physically felt, which allows divers to remain oriented and ensure they do not become disoriented in zero visibility conditions. This practice emphasizes the importance of teamwork and the use of tactile cues, which are vital for diver safety in such challenging underwater environments.