While wind-surfing near the seaside community of Port Harbor, a young man is killed by a giant great white shark. Horror author Peter Benton and professional shark hunter Ron Hamer realize the truth, but ambitious mayor William Wells refuses to accept that a shark threat exists, fearing that a cancelled wind-surfing regatta would derail his campaign to become state governor. Wells has shark nets installed, but the sounds of teenagers splashing in the surf leads the shark to rip through the nets. The next day, the shark plows through the wind surfers, knocking them off their boards, before targeting the mayor's aide and eating him.