Professional scuba diver Drake Andrews is first approached by ship magnate Robert Radcliffe. Exploratory dives indicate that the complete descent would be too hazardous, and Andrews refuses the assignment. Radcliffe then enlists the aid of a stunning blonde named Jill Talley, to induce Andrews to change his mind. Meanwhile, Andrews' diving partner Larry Lahr meets Captain Leo Stohl, skipper of the second ship involved in the collision, and is convinced that Stohl was not at fault. Andrews eventually accepts to make the descent for Stohl, facing dangers that are not all seaborne.
—Jorge Reinaldo Galindo Porras