Meanwhile in the galley, seaman Arnold Cane (Frank Whiteman) crawls underneath a shelf to set up a small explosive device.

In a underwater cave hewn out of the rock former US Navy Captain Morgan Grayland (Stephen Elliott) and his marine-biologist daughter Cynthia (Pamela Hensley) closely monitor the sub’s descent as they await the precise moment to detonate the bomb.

After hearing Steve’s account of the incident, Admiral Prescott orders an evaluation team down to the sub to make a damage report, but Cynthia’s trained sharks has them hurrying back to the surface.

Steve is then lowered down to the Stingray but halfway there, a shark snaps the cable, sending him crashing on the ocean floor.

Cynthia is pleased to inform her father that the repairs will soon be over, but Steve gladly adds a few hours to maintenance time when he yanks out the steering wheel out of its socket.

Lying on his cot, Steve keeps a keen eye on his guard while casually fingering a message in Morse code against the rock wall, hoping the ship’s hydrophone would pick it up, but Cynthia is quick to cut the message short before Rudy has a chance to decipher it.

If indeed Admiral Prescott receives confirmation of nuclear missiles on board the Stingray he will be faced with no other alternative but to destroy the submarine whether Steve is aboard or not .

While keeping a gun trained on Steve Cynthia explains the reasons behind this hijacking. They are to show the government that her father’s theory on trained sharks is proven effective. For years he fought the crummy system that unceremoniously trashed his project of using sharks in underwater warfare on account of one fatal casualty. And now he will finally receive the accolade he so richly deserves.

Grayland adds that this nuclear power will give him the leverage her needs to bring down the government by using the Stingray as a threat to other submarines to fork over their precious cargo.