Mitch Buchannon has just been promoted to lieutenant. Mitch and his ex-wife Gayle have an argument about what's best for their son Hobie. Eddie Kramer is the top rookie in the rookie class of '89, and Shauni McClain is one of the last ones to qualify. Shauni starts off as a terrible lifeguard, but the experienced Jill Riley teaches her how to become a good lifeguard.