Michael Powell had been a big fan of Noel Coward's In Which We Serve, which acted as inspiration for him.
Michael Powell later published a novel, "The Last Voyage of the Graf Spee", retelling the story mainly for children.
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.
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.
Attention to detail was particularly important to the producers, so all the naval procedures depicted in the film 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.
First cinema film of Donald Moffat.
First feature film of Jack Gwillim.
HMS Battleaxe was also used as a camera ship (off Malta).
HMS Birmingham was used as a camera ship.
Location filming started on 13 December 1955, the 16th anniversary of the battle. The River Plate Association in Auckland sent a good-luck message to the crew. "Congratulations on choice of day. Hope your shooting will be as successful as ours!"
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.
Niall MacGinnis was offered a role in this project.
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.
Ships used in the film: HMS Sheffield as HMS Ajax, INS Delhi (HMS Achilles 1933-41, HMNZS Achilles 1941-46) as HMS Achilles, HMS Cumberland as HMS Cumberland, Heavy Cruiser USS Salem as the German pocket battleship Admiral Graf Spee. Light cruiser HMS Jamaica played the played the part of heavy cruiser HMS Exeter.
The Admiral Graf Spee was portrayed in the film by the USS 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.
The film omits the tragic final act of the story. A few days after scuttling his own ship, German Captain Langsdorff committed suicide in a hotel room in Buenos Aires. He was dressed in full uniform and wrapped in the battleflag of his sunken vessel.
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.
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 HMS Hood and HMS Resolution.
The US Navy would not allow any Nazi insignia to be displayed on the USS Salem. Footage of the wartime German flag and other insignia was filmed on British ships.
The USS Salem was a WWII-vintage Des Moines class heavy cruiser, armed with nine 8-inch guns. In this movie we can also see the 3-inch AA guns installed to combat Kamikaze attacks.