What should a lifeguard do if working alone and sees a swimmer in distress?

When a lifeguard sees a swimmer in distress while working alone, the appropriate response involves using a rescue device and performing a rescue while also ensuring that communication equipment is ready to call for help. This is crucial because the lifeguard must prioritize both the safety of the distressed swimmer and their own safety. Using a rescue device allows the lifeguard to maintain a safe distance while assisting the swimmer, reducing the risk of needlessly jeopardizing their own safety.

Simultaneously, having communication equipment ready is essential as it allows the lifeguard to alert additional help once the immediate situation is under control. This two-pronged approach ensures an effective response - providing immediate assistance to the swimmer while also securing the availability of additional help if needed.

The other options do not adequately address the safety and effectiveness required in a lifeguard's response. For instance, waiting for others to help would unnecessarily delay assistance, and simply shouting for help does not provide the immediate intervention required for a swimmer in distress. Jumping in without a device increases the risk of drowning for both the lifeguard and the swimmer, which is contrary to the lifeguard's training and responsibility.