What is the purpose of the "10/20" rule in lifeguarding?

The "10/20" rule in lifeguarding is designed to enhance the effectiveness of surveillance and rescue operations. The essence of this rule is that lifeguards should be able to visually scan their assigned area every 10 seconds and reach a distressed swimmer within 20 seconds. This systematic approach ensures that lifeguards maintain an attentive observation of their surroundings, allowing them to quickly identify any potential emergencies. The 10-second scan interval encourages constant vigilance and awareness, while the 20-second response time sets a standard for prompt action to assist anyone in need of help. This framework is crucial for maintaining safety in aquatic environments, enabling lifeguards to intervene swiftly and effectively.

The other choices do not accurately capture the critical function of the "10/20" rule in respect to surveillance and response times, which are essential in ensuring that lifeguards can provide timely assistance to swimmers in distress.