A dangerous crime wave hits the beach in Emerald Bay, Florida. So, Lt. Mitch Buchannon and his team of lifeguards, including a brash new recruit, team up to uncover a local criminal plot that threatens the innocent and their future. They are on a mission to prove that you don't have to wear a badge to save the bay. 

Mitch Buchannon, who supposedly died in "The Killing Machine", is recovering from amnesia in Los Angeles. He returns to Hawaii to marry Allison, a woman who looks like the late Stephanie Holden, but who's actually part of a revenge plot by Mitch's old nemesis Mason Sato (from "War of Nerves").

The final episode of the series. Leigh is getting married as Sean contemplates a job offer from Australia with their lifeguards. He's also still dealing with his feelings for Leigh as he tries to choose between the two.

Sean turns down a free week at the Hilton Hawaiian Village after saving a local TV celebrity, so Zack goes in his place.

Sean, Jason and Zack participate in a natural obstacle course.

Sean and Leigh are held captive by the head of a local company that's using toxic chemicals to create a man-made reef. Zack accidentally breaks a friend's paddle and tries to replace it.

Jessie returns to Baywatch Hawaii with news that she's entered to race in the Ironman Triathlon. Making things worse is the fact that she discovers that JD and Kekoa are seeing each other and complicating the fact that she wants to get back together with him.

Jason, J.D., Kekoa and Zack are sent to Kauai to go on a trip with Britt, the daughter of one of Baywatch's sponsors. In the meantime, Sean and Brian make a rescue of Matt, a boy all new to windsurfing. Afterwards, the brand new computer system at HQ breaks down. Sean was supposed to show this system to the sponsor coming over that day, so he's pretty stressed out. Matt shows up later on and offers his help to fix the computers, and he's able to do so right before the sponsor shows up. In Kauai, J.D. and Kekoa are bickering about a watch J.D. got from Jessie. They decide to stand by at the low-land to sort out their problems while Jason and Zack leads Britt away. They're both arguing for Britt's attention.

Sean and Jenna save a man who got his head smashed against some rocks while surfing. A friend of the victim starts a romantic flirtation with Jenna. He is working with finance, and Jenna wants him to help her with some investments. In the meantime, Jason and J.D. spends some time with Derek, a childhood friend of J.D. They soon find out that he has got a lot of personal troubles, and that he's going to put J.D. in a life threatening situation. Later on, Jenna gets drugged by her new romance. He's trying to run off with her money, and Jenna contacts Sean for backup.

There's a hurricane coming, and the lifeguards at the Baywatch headquarters are all preparing for the worst. In the middle of this mess, Jenna sends a false rescue to Sean because she needs a ride back to HQ. This puts them both in a dangerous situation as the storm is approaching when they're far away from the other lifeguards. They accidentally crash their Scarab and find shelter in an old military bunker. A tree falls over the entrance making it impossible for them to get out, and later on it's starting to leak water into the small bunker. Sean manages to find a drain, but the water is not draining at the same speed it's flowing in. They both realize that they're going to drown in there, and share a lot of personal experience with each other. At HQ, Zack is all alone with his music and Jason's donuts. All of a sudden, a tourist approaches. He later finds out that she's a freelance journalist named Ivy, searching for some big news to get on television. She is so desperate that she's going to put them both in danger.

Kekoa's father visits her beach. During his visit, he's saved by a junior lifeguard. During the same time, another vacationer complains to Sean that his gold watch has been stolen. As these two incidents merge, Sean is served with two lawsuits and restricted from having any contact with the beaches or the lifeguards. In the aftermath, Kekoa's father, who filed one of the lawsuits, suffers a severe stroke after Kekoa confronts him about going after the center just to break up her marriage to J.D.

Carrie, one of the rookies who was made a permanent member of Baywatch Hawaii, helps rescue a pair of scuba divers. After the rescue, one of the divers becomes infatuated with Carrie and begins stalking her. Sean becomes suspicious of this stranger and it quickly becomes apparent as he begins showing up everywhere Carrie is. After Sean, Jason and Zack saves Carrie from the stalker, she realizes that she's no longer safe and that she's not cut out to be a lifeguard. The incident has left her shaken up as she leaves Baywatch Hawaii for good.

During a rescue, Jenna's reckless behavior places her life in danger and that of Zack, who rescues her, in return. Because of the rescue, Zack is in danger of losing his hearing because of the rescue which stirs up feelings of remorse on Jenna's part. Sean discovers that the rescue was a false alert and discovers that it was Councilman McKenna's own son who was calling in the false alerts which put Jenna and Zack in danger in the first place. Pat Morita (The Karate Kid) makes a guest appearance as Kekoa's father.

A millionairess is vacationing in Hawaii with her husband who dies while swimming. Complicating matters is a new police chief who is giving Sean more problems. As Sean attempts to unravel the mystery of the murder, she accuses him of molesting her on the beach and draws the ire of the new police chief.

Zack and Jason befriend a man and his daughter who are on the run from the man's ex-wife. Sean promotes Carrie to lieutenant despite Zack's attempts to catch a purse snatcher.

Sean sees visions of his dead son after a teenage friend dies on a surfboard outing. Jason, JD, Leigh and Carrie are forced to have Jenna on their team in a lifeguard competition.

Sean deals with a notorious "shark tour" provider. Jason has problems with a bumbling tourist trying to impress his son. JD and Kekoa try to keep their relationship a secret.

Zack endangers JD and Kekoa during a rescue and is placed on suspension. Complicating matters is Jenna who shows up and takes possession of a Scarab and two Jet Skis. While Zack is on suspension, he meets a mysterious woman who has him on a new path. Finally, Kekoa, after realizing how close JD came to losing his life during Zack's rescue, starts to realize she's falling in love with JD.

Danny reluctantly joins the rookie team when he gets into trouble with the law again. Kekoa moves out of her father's home. Two women steal Zack and Jason's truck.

Jason becomes smitten with a volleyball player who has a heart disorder. Jenna takes advantage of the tension between Sean and Leigh.

Leigh falls for an adrenaline junkie who might put her life at risk.

Leigh gets jealous when Sean becomes attracted to a new team sponsor.

Sean's relationship with JD begins to get more complicated as JD begins to feel resentful about being on the team. Making things even worse is Kekoa's ex-boyfriend, who has returned to win her back. Kekoa's life gets even more complicated when she's threatened with a lawsuit from the father of a teenager who endangered the life of a married couple who were swimming at a beach.

A new group of recruits have arrived to be trained at the new Lifeguard Training Center. Making things worse is Jenna, who has returned to oversee the LTC, making life even more difficult for Sean. Adding to the problems is Sean's friend Cliff, who has troubles of his own.