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 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.

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.