The lifeguards of the North Shore experience the most dangerous ocean conditions the district has seen in years. Sonny assigns Laka as acting lieutenant as Em has the day off and joins Jenn to catch some massive waves. Meanwhile, Kainalu's father pressures him to leave his shift and help him with his campaign over patrolling the beaches. Hina thinks she is ready to back-up the rescue skis, and Laka and Will almost make it through the day when a fight breaks out among locals. Emotions reach a boiling point for Sonny when he experiences another loss.