Giant prehistoric mollusks (or are they aquatic caterpillars) rise from the Salton Sea and create hell for local bathers and a short tempered Naval toughie (Tim Holt) in this above average  giant bug flick. The low budget monsters are decent for a film of this type, particularly in the underwater scenes where they commit some pre JAWS chomp downs on a few unlucky swimmers. Fun to wach Holt’s gruff character bark at his co-stars in a number of scenes.