A killer whale is capsizing boats and endangering scuba divers and swimmers along a stretch of coastline.

A pair of prospectors hire Mike to trace the source of radioactive fish with a Geiger counter in hopes of finding a uranium deposit.

Mike faces sharks and other unexpected difficulties while working with three pretty women undergoing astronaut training.

A professor and his daughter hire Mike to help them search for a rare underwater plant in Costa Rica.

Mike leads a diving team in rescuing a Latin American diplomat and his family from kidnappers.

Mike investigates reports of a sea monster off the coast of Mexico.

A famous newsman, convinced that he has a fatal illness, tries to end his life in such a way that his wife can collect his insurance, with Mike as a witness.

While working for the U.S. Treasury to break a counterfeiting ring, Mike intercedes in a kidnapping.

Mike interrupts an underwater survey in the Gulf of Mexico in order to save a diver whose air line has become snarled.

Latin American revolutionaries recruit Mike to recover the body of their murdered leader from the palace lagoon in order to ignite an uprising.

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

A beautiful woman plots revenge against Mike after flunking out of his class for scuba diver instructors.

Someone attempts to kill Mike while he's scouting out a site for an underwater marine preserve.

Mike trains a pair of frogmen for a rescue mission in which they will rescue their kidnapped president from an ancient fortress.

While investigating the cause of a mine flood that killed thirty men, Mike stumbles upon an air pocket with two survivors.

An attractive magazine photographer hires Mike to assist her in getting pictures of a sunken barge off the coast of Mexico.

The State of Florida hires Mike to organize and train an underwater police force to deal with a series of underwater crimes.

While looking into the possibility of linking two Latin American lakes by a canal, Mike runs afoul of rebel guerillas.

A coastal fisherman wages a private war against kelp harvesters, blaming them for ruining the fishing grounds necessary to his livelihood.

A swimsuit designer hires Mike to do an underwater fashion shoot, but corporate espionage interferes with the job.

While checking the underwater security of a new dam, Mike discovers a bomb that has been placed in an intake valve.

A young skindiver is found murdered after stealing lobsters from an elderly fisherman as an initiation stunt.

Working for the State Department, Mike attempts to rescue a political prisoner in South America by using a harbor city's canal system.

While surveying a remote river in the South American jungle, Mike is threatened by the jealousy of a man prospecting for emeralds with his wife.

After being accidentally caught in a fishing net, Mike challenges an Asiatic warlord by trying to retrieve a cache of medical supplies that the dictator has dumped into a river.