A diver on the surface waving their hand overhead and thrashing violently indicates what?

A diver on the surface waving their hand overhead and thrashing violently indicates distress. This behavior is a common signal that a diver is having trouble and requires assistance. When a diver is in a state of distress, they may exhibit erratic movements due to panic, confusion, or physical difficulties, which can manifest as thrashing or waving.

This signal is critical as it alerts nearby divers or surface support to the fact that immediate action may be required to ensure the diver's safety. It contrasts with other states, such as excitement, which would typically be characterized by more controlled and positive movements, rather than frantic ones.

Moreover, while a signal for assistance can sometimes involve waving, the context of thrashing suggests a more urgent situation than a simple request, indicating a need for immediate help rather than just signaling for assistance or expressing excitement. Keeping an eye out for such signs of distress is vital for the safety of all divers involved.