A group of scuba divers meet each other during a dive in the Pacific to find a sunken treasure. They also find a huge sea beast that threatens to devour them unless they can work together to outwit the creature. Using a floating mine that was lost by a mine-sweeping boat, they manage to destroy the beast before it can get to the mainland. Proving they work well together, the four strangers become friends, and together they form the "Sea Devils"

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