The personal and professional lives of the heavy-water lifeguards who patrol and protect the North Shore of O'ahu the most famous and dangerous stretch of coastline in the world.
Two rookie lifeguards, Hina and Kainalu try out to be on the team, as Sonny and his family are still grieving the loss of his nephew and Em and Will's past romance is revealed.
Sonny, Em, and Will race into action to save a young tourist, and Em places her own life in danger. Laka supervises rookies Kainalu and Hina's first day on the job.
Em is left in charge, Hina and Kainalu have beachside emergencies, and Will's fiancé visits him at work.
Two college kids get trapped in a collapsed sandpit; Sonny, Will, and Laka race to rescue people stranded; and Will learns if he made the cut for the firefighter job.
Em has the day off, Kainalu helps his father with his campaign, and Hina thinks she is ready to back-up the rescue skis.
The North Shore community comes together for Rocky's paddle out; Hina thinks about switching districts; Laka, Will and Kainalu try to save a beachgoer that accidentally speared his own foot; romance heats up between Sean and Em.
Will, Laka, and Em try to rescue an influencer. Kainalu and Hina discuss setting boundaries, and Mayor Emerson makes good on his word.
Sonny, Em, Will and Laka try to find missing paragliders; Kainalu invites Hina to a party with his ex-girlfriend.
A grandpa is rushed to the hospital. Plus, Sonny is not ready to become lieutenant, Chief wants Kenji to replace Sonny as Captain.
The team races to the rescue in the aftermath of an ATV accident. Romantic tensions are high between Em and Will as well as Kainalu and Hina.
Em and Will's relationship struggles as his fiancé returns, Kainalu asks Laka for help, and the team races to rescue locals from an inflatable Supsquatch accident.
As the state of Hawaii is under an evacuation order following a tsunami advisory, Captain Sonny has bigger issues when Ocean skips school and he can't find her.
Captain Sonny and the Ocean Safety team face their most dangerous rescue yet when a literal minefield is discovered on the ocean floor.
Captain Sonny, Laka, and Kainalu race to rescue cliff jumpers. Hina has family issues. Meanwhile, Will and Em hope to get over each other by rebounding with other people.
The team searches for two missing teenagers stranded in the middle of the ocean, Will doesn't get along with a new team member, and Em gets a surprise visit.
Em takes the day off to spend time with her mom but races into action when she comes across an unresponsive cave diver. Will confides in Vince about his personal anger issues.
Will and Em race to rescue a windsurfer that wipes out and suffers cardiac arrest. Meanwhile, Captain Sonny reunites with Ocean over a family lunch and Em realizes her mom is back to her old ways.
Laka and Will discover an unconscious man amid drug paraphernalia. Em meets a disabled veteran, while Hina reveals her feelings to Kainalu. Captain Sonny learns about Vince.
Hina and Kainalu help search for two missing snorkelers. Captain Sonny takes matters into his own hands about Vince, Will and Julie meet for coffee, and Em gets a job offer.
