powered by AFI
City Beneath the Sea is based on the legend of the city of Port Royal, which sank into the sea off the coast of Jamaica when an earthquake hit in 1692, killing five thousand inhabitants. According to a November 1949 Hollywood Reporter article, producer Albert J. Cohen bought the rights to Harry E. Reiseberg's book I Dive for Treasure, which included the short story "Port Royal...City Beneath the Sea," then hired Reiseberg to recreate a salvage dive that he had undertaken years earlier at Silver Shoals.
A May 1952 New York Times article and studio press materials detail how the film's underwater special effects were achieved: actors Robert Ryan and Anthony Quinn shot their diving scenes on an above-ground set, and were made to appear to be underwater by a special effects crew, who later hand-painted air bubbles and superimposed footage of water onto the shots. Universal press materials add that for these scenes, the camera were speeded up to approximate the more deliberate pace of underwater motion. Press materials also state that a crew of more than 100 created a 10,000-square-foot replica of the city of Port Royal. Modern sources state that footage of Reisenberg's actual dive also was included in the finished film.
Mala Powers was borrowed from RKO for the production. Although an April 1952 Hollywood Reporter news item adds Kathleen Freeman to the cast, she was not in the released film. In an August 1952 article, Hollywood Reporter reported that screenwriter Ramon Romero, backed by the Screenwriter's Guild, brought charges against Universal over the onscreen credits, which he felt should have credited him and Jack Harvey with "original story and screenplay." The parties settled on an undisclosed payment. An August 1953 item in Variety noted that agents Mark Herstein and Harold Cornsweet sued Reiseberg, Cohen and Universal for $25,000, asserting that Reiseberg made a deal with them to buy his book but then gave it to Cohen. The disposition of this suit has not been determined.