April, Lani and J.D. are on patrol in the scarab, when they notice a boat and suddenly see that two men are knocked into the water by a boom. They go there to rescue them, and the third one is knocked into the water as well. The owner of the boat is named Captain Bob. He is very grateful and tells them that he owes them one. They discover that Captain Bob and his sons are diving for sea urchins, and they earn a lot of money by selling the sea urchins.
This long-running series follows the adventures of a team of lifeguards on the crowded beaches of Los Angeles County. Veteran lifeguard Mitch Buchannon watches over the younger lifeguards that come and go with each passing season as they keep the beaches safe for vacationers. Frequently he must take action to save them from the raging seas and from the raging tempers that sometimes flare up between the young guards in this stressful job.