What is the primary risk associated with overhead environments in wreck diving?

The primary risk associated with overhead environments in wreck diving is the inability to ascend directly to the surface. Overhead environments, such as wrecks, caves, or other enclosed spaces, limit a diver's ability to make a direct vertical ascent. This creates a heightened risk of situations such as disorientation, becoming trapped, or suffering from a medical issue—since the diver has fewer escape routes available compared to diving in open water. In emergencies, being unable to ascend quickly can lead to serious implications, such as an increased risk of decompression sickness.

Limited visibility can indeed be a concern in wreck diving, but it is not the fundamental risk that arises specifically from being in an overhead environment. Poor weather conditions can affect surface conditions but do not directly pertain to the overhead environment itself. Likewise, the absence of marine life is not a primary concern for safety in wreck diving and does not pose a risk as significant as the inability to ascend freely.