An overconfident swimming champion endangers both herself and Mike when she challenges him to an underwater race to Catalina.

After discovering a sunken Japanese submarine, the amateur skin diver who found it goes violently berserk.

A Greek sponge diver and his pretty girlfriend lay a minefield for Mike, fearful that he will interfere with their discovery of a valuable statue on the Mediterranean seabed.

Mike defies tales of a mysterious sea serpent when he searches for a shipment of stolen liquid explosives in Arabia.

Mike investigates the mysterious death of the featured performer in a water ski show during the act's underwater finale.