The original English version of this movie omits the tragic final act of the story. A few days after scuttling his own ship, German Captain Hans Langsdorff committed suicide in a hotel room in Buenos Aires, Argentina. He was dressed in full uniform and wrapped in the battle flag of his sunken vessel. In the German dubbed version, the final voice-over was changed to explain what happened to Langsdorff.
The Midshipmen's quarters were empty because Captain Langsdorff had promoted all of his Midshipmen to Ensigns in order to make room for his prisoners.
There was strong speculation than German Captain Hans Langsdorff committed suicide rather than face the humiliation of losing his ship. There was even more speculation that he did it because he feared what Adolf Hitler would do to him if he returned to Germany. At the time, the Graf Spee was the pride of the German Navy, and scuttling her would have been regarded as treason.
Attention to detail was particularly important to the producers, so all of the naval procedures depicted in this movie are completely accurate. The scene where Harwood meets with his Captains on-board the Ajax, however, was a fictitious one, created in order to explain the situation to the audience.
River Plate is a mis-translation of the Spanish name for the river, Rio de la Plata. "Plata" is Spanish for silver and "Plato" is Spanish for plate. The river is actually called the Silver River.
The photo of the Admiral Graf Spee in the Captain's cabin was taken at the Fleet Review in Spithead in 1937. The two ships in the background are H.M.S. Hood and H.M.S. Resolution.
Michael Powell had been a big fan of Noël Coward's In Which We Serve (1942), which acted as inspiration for him.
H.M.S. Cumberland "played" herself. However, she had been withdrawn from frontline service and was being used as a gunnery trials ship, with various prototype turrets installed from time to time, so that they could be evaluated. When she appears towards the end of the movie, it is obvious that her forward turrets (A and B) have been removed, and a small prototype turret installed in the X (aft) position. H.M.S. Cumberland was finally scrapped two years after the shooting of this movie.
Location filming started on December 13, 1955, the 16th Anniversary of the battle. The River Plate Association in Auckland, New Zealand sent a good-luck message to the crew. "Congratulations on choice of day. Hope your shooting will be as successful as ours!"
The U.S. Navy would not allow any Nazi insignia to be displayed on the U.S.S. Salem. Footage of the wartime German flag and other insignia was filmed on British ships.
Most of the sea action was filmed on real ships. The producers were lucky enough to have various ships of the Royal Navy's Mediterranean Fleet at their disposal.
Ships used in this movie: H.M.S. Sheffield as H.M.S. Ajax, I.N.S. Delhi (H.M.S. Achilles 1933-1941, H.M.N.Z.S. Achilles 1941-1946) as H.M.S. Achilles, H.M.S. Cumberland as H.M.S. Cumberland, Heavy Cruiser U.S.S. Salem as the German pocket battleship Admiral Graf Spee. Light cruiser H.M.S. Jamaica played the part of heavy cruiser H.M.S. Exeter.
Michael Powell later published a novel, "The Last Voyage of the Graf Spee", retelling the story mainly for children.
According to the book "The Golden Gong--Fifty Years of the Rank Organisation, its Films and its Stars" by Quentin Falk, this movie was " . . . the last of the Archers' true collaborations" with a return to the Rank Company during the mid 1950s after Michael Powell and Emeric Pressburger had left after The Red Shoes (1948).
The U.S.S. Salem was a World War II-vintage Des Moines-class heavy cruiser, armed with nine eight-inch guns. In this movie, we can also see the three-inch AA guns installed to combat Kamikaze attacks.
The Admiral Graf Spee was portrayed in this movie by the U.S.S. Salem, despite the latter having the wrong number of main turrets. Of course, they weren't able to scuttle the real Salem, so that was the only real occasion that models were used extensively.
John Schlesinger, then an actor, is listed in the credits as Prisoner on the Graf Spee. In actual fact, the future director played a German Officer, the young Lieutenant who escorts Captain Dove to the ship after the Africa Shell is sunk, and introduces him to Langsdorff.
This was Writers and Producers Michael Powell and Emeric Pressburger's most financially successful movie.
After Christopher Lee (Manolo) retired from the role of Count Dracula with The Satanic Rites of Dracula (1973), John Forbes-Robertson (Lieutenant McBarnett) succeeded him in The Legend of the 7 Golden Vampires (1974), the ninth and final film in the Hammer "Dracula" film franchise.
The historical English name "River Plate" uses an obsolete sense of the word "plate," which was used extensively as a term for "silver" or "gold" from the 12th century onwards, especially in Early Modern English. The estuary has been known as the River Plate or Plate River in English since at least the time of Francis Drake. This English version of the name served as an inspiration for one of Argentina's most important football clubs, Club Atlético River Plate. A more literal translation of the name is "Silver River", though this is virtually never used in practice.
The harbour where the Graf Spee is shown moored in Uruguay is Grand Harbour, Valletta, Malta.