What indicates that a lifeguard is in need of assistance?

A lifeguard signaling for assistance is crucial for maintaining safety in aquatic environments. When a lifeguard extends one arm, it serves as a universally recognized signal indicating that they require help. This gesture allows other lifeguards or nearby personnel to understand that there is a situation needing additional support.

In contrast, other options such as both arms raised typically signify a more urgent situation, often indicating that a swimmer is in immediate distress rather than the lifeguard themselves needing assistance. Holding a buoy might indicate readiness to assist, while using a whistle generally serves as a tool for communication or to get attention rather than a distress signal. Thus, the correct signal for a lifeguard in need of assistance is the extension of one arm, clearly conveying the need for help without causing unnecessary alarm.