In overhead environments, what additional concern must be addressed compared to open water diving?

In overhead environments, such as caves or wrecks, navigation support becomes an essential concern that diver training emphasizes significantly. Unlike open water diving, where the surface is always visible and serves as a reference point, overhead environments can disorient divers due to the complexity of the environment and the lack of natural light.

Divers must ensure they have an effective navigation system and reliable support, such as guide lines or markers, to safely navigate through these confined spaces. This adds a layer of complexity to diving since divers need to be aware of their entry and exit points and plan their route carefully to avoid becoming lost, ensuring a safe return to the surface.

In contrast, elements like visibility, breathing patterns, and pressure changes are also crucial for diving safety, but they do not pose the same unique navigational challenges that are inherent in overhead environments. Thus, navigation support is a primary focus for safety in these situations.