After an earthquake leaves the California coastline in ruins and lawlessness prevails, a gang of ruthless surfers, led by the sadistic Adolf, seize control of the beaches. They dub themselves the Surf Nazis and rule the waves with an iron fist, terrorizing the remaining inhabitants and anyone who dares to defy their self-imposed dominion. Their reign of terror extends from assaulting innocent people to battling rival gangs that seek to challenge their dominance, asserting their authority through intimidation and violence.

The Surf Nazis' barbaric actions eventually lead to the murder of a man who was simply out to enjoy the sea. His death draws forth an unanticipated adversary—his mother, Eleanor "Mama" Washington. Outraged by her son's senseless killing and the anarchy that has consumed the community, she embarks on a relentless quest for vengeance. Armed and undeterred, she becomes a fierce opponent, infiltrating the gang's domain to thwart their operation and deliver retribution, unraveling the surfers' hold over the land.