Final answer:
A rescue is an act where a lifeguard needs to intervene to assist a swimmer in reaching the surface of the pool or the deck, which is crucial for aquatic safety.
Step-by-step explanation:
A rescue occurs when a guest would not be able to get to the pool surface or deck without lifeguard intervention. Lifeguard rescues are critical safety measures that ensure the well-being of swimmers in aquatic environments. It is essential for lifeguards to be vigilant and prepared to act swiftly to prevent drownings and other incidents in the pool. Therefore, a rescue is an important term in aquatic safety, referring to the act of saving someone from danger or harm while swimming.