Tagline: Up from the forbidden depths comes a Tidal Wave Of Terror!
Swimming near a Mexican village that has been terrorized by a sea monster, Julie Blaie (Anne Kimball), and American artist, is terrified when an object rises to the surface. It turns out to be a one-man submarine piloted by biologist Steve Dunning ('Stuart Wade' (qb)). Later an abalone diver vanishes and Julie faints after seeing the monster's eye rise from the sea. Pablo (Wyott Ordung) and Tula (Inez Palange) plot to offer Julie as a sacrifice to their gods. Pablo deliberately attracts a shark while Juilie is skin-diving, but she escapes, and her line snags an object that Steve and Dr. Baldwin (Dick Pinner) establish as part of a huge sea monster.