In what scenario would a lifeguard actively engage in a water rescue?

A lifeguard actively engages in a water rescue when a swimmer is in immediate danger. This is critical because the primary responsibility of a lifeguard is to ensure the safety of all individuals in the water. Immediate danger could involve situations such as a swimmer struggling to stay afloat, showing signs of distress, or requiring assistance due to fatigue or medical emergencies.

In contrast, a swimmer who is resting or simply playing games is usually not in need of immediate intervention, as these activities do not typically pose a threat to their safety. The lifeguard's actions are guided by assessments of risk and safety, making timely rescues essential when lives are at stake. In scenarios where no one else is watching, while it might indicate increased risk, it does not automatically necessitate action unless there is clear evidence of a swimmer in distress. Thus, the focus is always on assessing the urgency of the situation and prioritizing rescues when someone's safety is compromised.