ocean depths among other man-eaters of the deep.

Hugo proceeds to gather a group of fellow adventurers; Josh Owens (DAVID LADD), electronics expert; Victor (Vic) Spivak (CHUCK WOLLERY), explorer and diver; last, but not least is Zabby (CHERYL STOPPELMOOR), a gorgeous girl of pleasing dimensions and an adventurous spirit. The group travels cross-country to Florida and from there to Jamaica where they soon discover that they have more to fear than just sharks. Somebody is out to stop them. An attempt by a hired thug to steal their diving equipment ends in the death of the would-be thief after a wild chase through the island's forest roads.

A friend helps Hugo and the others charter a salvage boat, captained by Asper - (ROSEY GRIER), a friendly giant of a man who knows the danger-filled waters like the back of his hand. A new member is added to the group: Darby (DARBY HINTON) a youngster who helped chase the man who attempted to steal the diving equipment.

As the adventurers search for the sunken ship's location, they're being stalked not only by the man-killers of the underwater world, but by an equally deadly human shark, a hired killer named Harry (ART MATRANO), sent to stop Hugo and his companions. His employer; an unknown individual who wants the galleon's contents for himself.

The group makes several dives. On one of them, Zabby comes face-to-face with one of the white sharks and only by a miracle is she able to escape the huge fish before he decides to attack. Finally, the group locates the galleon amid a graveyard of sunken ships. But disaster strikes; a plane being used in the search is wrecked in a tropical storm and money is needed to pay off the plane's owner. Hugo, Josh, Vic and Zabby accept a salvage job from two lawyers whose clients stand to receive an inheritance . The job: salvage three coffins from the hold of a sunken freighter.

Harry strikes during the operation and sets off an underwater explosion that rocks the freighter while Hugo, Josh and Vic are inside. Hugo and Vic escape from the ship, but Josh is trapped inside the cargo hold. In a savage battle with Harry and his partner, who are about to kill Zabby and Darby, a live grenade goes off, blowing up the heavies' boat. The great white shark that has stalked the expedition attacks, making quick work of Harry's partner before turning and tearing Harry's arm off. The screaming killer is pulled under the waves by the huge creature.

A passing helicopter gets Zabby and Vic to Port Antonio where Asper has the salvage boat ready. In a tension-filled race against time, Josh is rescued from the freighter's hold moments before his air runs out. The memory of the violence and the menace of the ever-prowling white shark causes the group to abandon their quest and return to the U.S.A.

But death still stalks the case. The map that started everything is being claimed by the niece of its murdered owner .. . . . she is now marked for death . . .