What is one common way cave divers communicate while underwater?

One common way cave divers communicate underwater is through writing. In the unique environment of a cave, where visibility can be limited and sounds may not travel well, divers often carry waterproof notepads or slates to convey messages to each other. This method allows for clear and precise communication, which is crucial in the potentially disorienting and often challenging conditions found in underwater caves. Writing provides a reliable way to share important information, coordinate plans, or address any issues that arise during a dive.

While other methods such as sign language exist, they may not be as widely adopted, especially in tighter spaces where visibility is poor. Additionally, high-pitched sounds and whistling are not effective as they can become distorted or lost in the water, making them unsuitable for reliable communication in cave diving environments.