Mitch's Zuma Beach lifeguard friend, Jake Barnes, learns that his Australian ex-wife has suddenly died. So he, Mitch, Alex, April, Cody, and Jessie go on a trip to Australia where Jake is to meet the eight-year-old son, Terry, that he never knew. Upon arrival, Jake with Jessie in tow, travel to the Avalon Beach Resort Club where Jake meets with Terry and his ex-wife's friend Allie Reese, a helicopter pilot and lifeguard at the beach club, where Jake and Terry seem to hit it off.

While Mitch, Alex, Cody, and April prepare for their race against the Australian lifeguards, Jake must choose between staying in Australia with Terry or returning home without him. But when Terry does not want to leave Australia, he goes missing which prompts Jake, Jessie, and Allie to look for him.

Mitch Bucannon, on leave in Oahu, Hawaii while he sorts out his thoughts during a mid-life crisis (his failed romance with Neely, his mother's recent death, and Hobie living on the East Coast), decides to form an international team of lifeguards in Hawaii called 'Baywatch Hawaii' for saving lives after a rescue of a family on a remote beach in which a little girl is put in a coma after being submerged.

During the first week of training for the new lifeguard team of Baywatch Hawaii, competition between Jessie and Kekoa, as well as Jason and J.D. threaten to turn the tryouts into an all-out war. Jason, at Kekoa's advice, visits an old Hawaiian native to look into his true Hawaiian roots, and Allie takes a job as a helicopter tour pilot to make some extra money for herself.

Sean and the rest of the team risk their lives when they help with the local Coast Guard in a daring rescue to save six kaiakers who have gotten stranded on Kauai's Pina Nova coast. After saving four of the kaiakers, including two in an enclosed lagoon, night falls and the search for the remaining two is called off.

The abrasive Sean tries to get the team, on a week-long holiday in Kauai, from giving into the island's sun-and-fun atmosphere and concentrate on a return to training.

After Jason risks his life in a rash attempt to save two scuba divers trapped on a reef, Sean threatens to throw Jason off the team if he doesn't change the way he thinks about the risks and lives of people in need of a rescue in which Jason is confined to a beach for the whole day to learn what the people that are there are confronted, with Sean keeping a close eye on him.

During a girls swim out in the ocean, Allie discovers a rare gold coin dating back to a ship that was lost in 1941 during World War II which allegedly contains un-circulated gold coins and rare artifacts somewhere off the Hawaiian coast.

Allie's relationship with Nick begins to heat up, especially after he suggests a commitment between them. Then things take a turn when Allie, Nick and the rest of the team must cooperate with the Coast Guard to rescue two people trapped on a disabled submarine 200 feet on the ocean floor.

A secret from Dawn's past could jeopardise her position on the team when she gets served with a civil suit from the spouse of a diseased lifeguard from when she was involved in a failed rescue while working as a lifeguard years ago in Florida with J.D.

Sean has his hands full in dealing with Jenna Avid, the new head of the Oahu North Shore lifeguards, who issues some stern recommendations to the team, which is overshadowed later that day when a group of nudist activists, lead by a certain Leesa Strickler, choose the beach near the Baywatch Hawaii headquarters as their place of protest against the establishment which Sean, Jason, Allie, and Dawn have also deal with the media circus that arrives too.

Sean faces a personal conflict where he tries to resist Kekola's flirting advances which leads her, Dawn and Allie to re-examine their own femininity in themselves.

During a long day when Sean takes Jenna out on a Scarab motorboat when after a rescue of a injured young boy from a offshore reef, Sean reveals a secret to Jenna that could threaten his position when he tells her about his own son, that no one knows about, who drowned years ago which ruined his life and paved his way to becoming a lifeguard.

Sean tries to keep his blossoming relationship with Jenna a secret to avoid upset and criticism from the rest of the team when he attends a lifeguard conference on Maui to speak about the dangers of drowning where Jenna, Allie, Kekoa, Dawn, and Jason are in attendance.

Another long day begins with Sean, Jessie, and Kekola trying to save a woman trapped in an air pocket beneath a coral reef and trying to escape from the dangerous sulphur fumes within the cave. After a rescue of three skydivers whose parachutes open late, Dawn find a number of similarities between one named Jerome, and her ex boyfriend Ryan whom she discovers that they are both the same person.