Watch Rescue: HI-Surf

The lifeguards of the North Shore experience the most dangerous ocean conditions the district has seen in years; Sonny assigns Laka as acting lieutenant; Kainalu's father pressures him to leave his shift and help him with his campaign.

Sonny, Will, and Laka race to rescue people stranded after a shark attack. Em catches the attention of Fire Captain Sean Harimoto (guest star Ian Anthony Dale). Will learns if he made the cut for the firefighter job. Hina makes a move with Kainalu. Sonny attends Zion's memorial fundraiser and attempts to reconnect with his sister for the first time since the funeral.

Em works to earn the team's respect when she is left in charge. Hina and Kainalu juggle multiple beachside emergencies. Will's fianc? pays him a visit at work. Sonny opens up to a former lifeguard about his trauma since losing his nephew. Laka continues his flirtation with EMT Jenn (guest star Sea Shimooka).

A flash flood sweeps a young tourist away from her family and out to deep sea; going against Sonny's wishes, Em takes a bold risk and places her own life in danger in hopes of rescuing the lost-at-sea tourist.

Captain Sonny Jennings and his core team of lifeguards monitor the dangerous Hawaiian waters; new lifeguard recruits compete to join Sonny's district; Sonny and his family grieve after the loss of his nephew; Em reveals a romantic past with Will.