During which scenario can children under 12 swim alone in the pool?

Children under 12 cannot swim alone at any time primarily due to safety concerns. Young swimmers may lack the maturity, judgment, and experience necessary to handle unexpected situations that can arise in a pool, such as fatigue, cramps, or encountering difficulties while swimming. Lifeguards are trained to supervise and ensure the safety of all patrons in the facility, but children also benefit from adult supervision to mitigate risks and ensure a prompt response to any emergencies.

While other options suggest conditions under which children could swim without supervision, none of these scenarios sufficiently guarantee safety. Even if a child is a proficient swimmer, they still may not possess the awareness or decision-making skills required to navigate potential dangers when alone. Therefore, the safest policy is to not allow children under 12 to swim unsupervised at any time, ensuring they are always accompanied by a responsible adult or lifeguard.