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.

Mitch's former wife is planning to move to Ohio and wants to take Hobie with her. Upset over the squabbling that ensues, Hobie takes off with a friend and runs into pirates on a nearby island. Eddie and Shauni squabble after Shauni accidentally hurts Eddie.

Gayle and Mitch continue to fight over Gayle's plan to take Hobie with her. She ultimately changes her mind after Hobie risks his life to save a drowning young girl. A plane crashes into the water near the beach with the occupants, after they are rescued, looking to recover a suitcase of stolen money that they had with them. Captain Thorpe decides to join Eddie and Shauni on their tower in order to teach them.

Mitch attends his high school reunion, rekindling an old flame with former wife Gail, while Eddie plays father for the day.

Hobie, a cold-hearted Gayle and Ken, Gayle's fiance, get trapped inside Ken's plane when it crashes in the ocean.

Hobie, Gayle, and Ken get rescued from the crashed plane; Matt's father takes back Matt's motorcycle; Jackie has problems with the renovation of her Summer Place.

Three months after the trauma of the massive earthquake, Hobie arrives back home after spending the summer in Ohio with his mother, Gayle, who asks Mitch marry her again in a formal ceremony on the beach. Everyone is delighted, except for Stephanie who still has feelings for Mitch.