Synopsis from the original press packet

Chubasco (CHRISTOPHER JONES) and his girl Bunny (SUSAN STRASBERG) are arrested during a free-for-all fight started when motorcycle bums ride through a swinging beach party attended by Chubasco and Bunny. Bunny's angry father, tuna boat skipper Sebastian Marinho (RICHARD EGAN), bails out his daughter and then, still in the San Diego police court, tries to strangle Chubasco whom he blames for Bunny's plight.

Judge North (EDWARD BINNS) dislikes sentencing Chubasco, only 20 and with a police record, and prevails upon a friend, cannery executive Nick Kassel (PRESTON FOSTER), to get a job for Chubasco aboard the tuna boat Edna Belle skippered by Laurindo (SIMON OAKLAND). Before his departure, Chubasco secretly meets Bunny in her garden at night and reveals his plans to leave the boat at a foreign port, away from court jurisdiction, and send for her so they can be married.

Chubasco's attitude makes him disliked by the crew, but his eye for spotting schools of fish soon wins him improved status. Sympathetic to Chubasco's police problem, Laurindo puts him aboard another tuna boat, the Salina from the foreign port of Puerto de Pescado, when the Edna Belle is ready to return to San Diego.

Benny (JOE DE SANTIS), skipper of the Salina, and Chubasco get along well. When Chubasco lands in Puerto de Pescado he has Bunny fly there and Benny arranges a wedding party for the couple at the Happy House, a shoddy night club and pleasure spot owned by generous and buxom Angela (ANN SOUTHERN). Guests are Angela's girls and men from the fishing boats.

Drunk and singing, Benny is led off by Angela to her bed where he dies of a heart attack. Chubasco's hope for steady work dies with Benny. Sebastian's tuna clipper, the Equator, battered by a storm, docks at Puerto de Pescado and Juno (RON RICH) the first mate, hires Chubasco, without telling Sebastian, to replace a crew member lost overboard. Sebastian does not discover who his new deckhand is until well out to sea.

Again Chubasco's keen eye for fish, and his skill in piloting the chase boat that keeps the tuna from escaping the slowly closing net, gains Sebastian's admiration. He's willing to forgive the boy. Then he learns on the ship's radio that Bunny has married Chubasco, and in a whore house. He attacks the boy and the two fight in silent fury on the boat stairways and deck, unseen by the crew in the dark.

Sebastian falls into the sea and Chubasco, though dazed, manages to toss out a rescue light and life ring and alert the crew. Rescued, Sebastian orders the Equator to head for Puerto de Pescado. "I want that kid off this boat," he says. In rough seas the boat pauses to haul in a big catch of tuna. A section of equipment, loosened by the rolling seas, knocks Chubasco into the net of churning fish.

As he sinks under water, Sebastian jumps into the net and drags him to the surface. Sebastian's experiences with the now revived boy have brought a change of heart. "As long as you're fishing for me, nothing is going to happen to you," he says. "Your wife would never forgive me."

When the boat lands at Puerto de Pescado, Sebastian lets Chubasco leap ashore first into Bunny's waiting arms.