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.

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.