What action should a lifeguard take if they notice someone engaging in unsafe behavior in the water?

When a lifeguard notices someone engaging in unsafe behavior in the water, blowing the whistle and calling for attention is an effective and immediate response. This action alerts both the person in danger and other beachgoers that there is a potential risk, prompting them to become aware of the situation. Using a whistle is also a standard protocol in lifeguarding, as it helps to convey authority and attract attention quickly.

In emergency situations or when someone's behavior poses risks—such as swimming beyond designated areas, diving in shallow water, or engaging in rough play—this quick response can prevent accidents before they occur. It creates an immediate awareness of the situation, allowing the lifeguard to assess whether further action, such as intervention or rescue, is needed.