What is a "safety buoy" used for in open water rescue?

A safety buoy in open water rescue serves a crucial role in monitoring safe swimming zones. These buoys are often placed at designated areas where swimming is deemed safe, helping to delineate boundaries for swimmers. This is essential for preventing accidents, as it guides swimmers away from potentially hazardous areas such as those with swift currents, rocky bottoms, or areas where boating traffic might be present.

Safety buoys can also provide visual cues for lifeguards and other safety personnel, making it easier to monitor and manage swimmer safety. In environments with varying water conditions and potential hazards, these buoys play a vital role in maintaining a safe space for recreational activities.

The other options provided address different uses of buoys or signals in water safety, but they do not encompass the primary function of a safety buoy, which is to establish a safe area for swimming.