What is a common practice for improving communication while deep diving?

Using hand signals and gestures is a common practice for improving communication while deep diving because underwater environments can hinder verbal communication due to the dense medium. Sound travels differently in water, making it difficult to hear speech clearly, especially at greater depths. Divers are trained to use a variety of hand signals to convey important messages, such as "OK," " ascend," " descend," and "something's wrong." This method is efficient and allows for quick, clear communication between divers, maintaining safety and coordination during a dive.

The other options are less effective for various reasons. Shouting underwater is impractical due to the way sound travels in water and would not convey messages effectively. Wearing radio equipment is not a common practice in deep diving because it can be cumbersome and not reliable at certain depths or in conditions where equipment might fail. Using color-coded buoy markers is more suited to surface signaling and navigation rather than direct communication with dive partners underwater.