Mitch is on a beach in Hawaii where he witnesses a family washed off the rocks. Mitch immediately reverts to lifeguard mode and pulls them from the water. He finds the daughter unconscious and rescues her too. She resumes breathing, but is still taken to the hospital in a coma.

Sean puts his lifeguard team to the test by first making them dive off a dangerous looking cliff, and then, making them swim back 3 miles from shore. However, the real test occurs during the swim when they must rescue passengers of a sunken boat. As the lifeguards move in, new roommates Kekoa and Jessie instantly clash. Mitch saves a Hawaiian girl from secondary drowning. Arriving in Hawaii with the scarab, Newmie springs into action after an explosion in the water. Allie finds employment as a helicopter pilot for a sightseeing tour. Jason meets a Hawaiian native, who tells him of his past and his destiny.

A new lifeguard, Dawn, joins the team, but blacks out during a swim. Sean gives her another chance to prove herself by challenging her to an underwater breathing contest, during which she has to come to his rescue. However, Sean was merely testing Dawn, who passed his test and he agrees to let her remain on the team. Dawn is reunited with her past love J.D., who declares their relationship is in the past. Mitch reunites with his foster son Tanner, who watches Mitch and Allie rescue 2 women from their overturned canoe. Tanner befriends a suicidal teenage surfer, who plans on taking her life during a suicidal wave ride. Mitch finds the girl and encourages her to be brave about receiving treatment for her diasease. JD tries out for and makes the America's Cup sailing team, but stays at Baywatch because he made a commitment to the team. Jason makes his first successful rescue when he helps a woman caught in a rip.

Baywatch and the Coast Guard mount a joint rescue operation, but mistakes are made by J.D. and Sean. To learn from their mistakes, Sean has the team train with the Cost Guards, during which Allie is smitten with Coast Guard Nick. Later, a training exercise becames a real rescue when Jason must come to Sean's aid. Jessie jumps to conclusions after finding JD in a compromising position with Kekoa and Dawn fans the flames. Jessie decides she and J.D. should "cool off" their relationship. After leanring of a Polynesian cleansing ritual from Sean, Jessie goes skinnydipping, but must come to the rescue of a swimmer. Sean comes to her aid by boat and gives the naked Jessie a swimswuit. Mitch and Tanner travel to Shark Island and learn about the Hawaiian legend of Mano, a man eternally seeking his lost son. At night, Tanner encounters Mano, who finally finds peace. Mitch and Tanner discuss Tanner's gang problems on the mainland and Mitch resolves they will face the problems together.

Baywatch teams up with the Coast Guard to search for a group of kids in the water. They all have to search in caves all they, but they still can't find all the kids. Allie is filming the caves with a camera with an infrared sensor to see what they have. When night falls, there's still two kids missing, but after watching over the film from their camera, they see what they think is a hand in one of the caves. They then decide to go out at night looking for the last ones, but soon discovers that the victims have been swept into another cave via an underwater channel.

Jessie and Kekoa face-off during a paddle boat trip of a local river in which they must co-operate with each other to rescue and transport a man to safety after his canoe falls down a waterfall. J.D. tries to get Jason to shed his Texan image in order to learn how to flirt with some attractive-looking ladies on the marina. Also, Sean accompanies Allie on a quest into an underwater cave in search of some Hawaiian archaeology.

Sean considers dismissing Jason from Baywatch unless he changes his attitude. A man and his pregnant wife need to be rescued from the ocean after falling overboard from their yacht.

Mitch is shocked when he finds out that Hobie is getting married to a woman he only met recently. The Baywatch lifeguards must undertake a dangerous rescue of a woman trapped in an underwater cave.

Jessie is unhappy that some men are hugging sharks. She eventually confronts the men and is actually slapped for her efforts. Later,she,Dawn,Allie,and Kekoa show up for a traditional Hawaiian ceremony. The women cheerfully put on crowns,leis,and sarongs over their bikinis. But then Kekoa informs them that they must remove their bikini tops! The women are hesitant,but then they cover themselves with many leis. Then,one-by-one,each girl unties her bikini top and takes it off. They perform a hula dance. With the background music,its actually a beautiful scene. At the end,Jessie is still down about the men hugging the sharks. Mitch goes skydiving with her. Jessie has a big smile on her face.

The news of a lost treasure's location excites most of the Baywatch lifeguards but the excitement quickly threatens to tear the team apart in the rush to find it.

An experimental submarine and its passengers ends up in a devastating tragedy for Allie, who finds & loses love all too quickly. She finally learns to trust Nick, a rescue swimmer working at the U.S. Coast Guard; a man she's been into for two weeks. Nick takes some huge risks when trying to save the passengers in the submarine, which unfortunately leads to him getting a severe case of the bends. He never wakes up, and Allie is devastated. Mitch arranges a lifeguard memorial service for Nick. Mitch tells her "Nick wasn't a lifeguard, but he died being one".

Dawn's past threatens to cause her problems in the present. A kid is caught in a storm drain and the Baywatch team races to rescue him before it is too late.

The amazing recovery of a man rescued after being submerged for a very long time inspires Dawn. Kekoa debates getting involved in another relationship as she thinks she dooms her chances for happiness with self doubt.

A diver bursts from the water in a panic: his girlfriend has gotten caught in a gill net. Jason and Sean immediately dive down and try to cut the girl free, but the net is very strong. The two lifeguards swim to the surface to get another breath of air. The girl's air hose gets stuck in the thin netting and is cut. Sean grabs a couple of bottles of spare air. Jason works frantically to cut her free, slashing up his own hands on the thin net. Finally, she is out and safe. The two swim towards their jet skis.

Sean finds himself having to deal with romantic overtures from unexpected sources. Jason gets caught up in a whirlwind romance with a woman visiting Hawaii.

Jessie and her Baywatch counterparts struggle to save a woman trapped in an underwater coral reef with a dwindling air pocket keeping her alive.

Jason, at the request of a young woman, goes to visit her father and reluctantly learns a craft from him. Sean's feelings about Jenna change abruptly when he finds out her plans for the future and how they will impact him directly.

As his trust in Jenna deepens, Sean decides to take a huge risk by sharing his most dark and emotional secret with her. He can only hope that Jenna will not betray his trust. Meanwhile, Allie struggles to keep up with a challenging day of rescues.

Jessie accepts an offer from her sister Dawn, who claims that she wants to help Jessie regain confidence by competing in a challenging triathlon. Sean and Allie worry about Jessie's health and wonder if Dawn might have darker motives behind her offer.

Sean and Jenna continue to develop feelings for each other, but Sean is afraid to go public with their romance. When he has a chance to lecture on lifeguard techniques, Sean welcomes the distraction. However, when Jenna ends up in grave danger, Sean's true feelings come to light in front of his team.

When Sean learns that a young man Jamal has dreams of becoming an Olympic swimmer, he decides to do whatever he can to help Jamal realize his goals. Meanwhile, Mitch has his hands full as he aids Jessie in overcoming a family crisis.

Mitch faces off against an eco-terrorist, and as the dust settles, Baywatchs' finest will never be the same.