Ships used in the film: HMS Sheffield as HMS Ajax, INS Delhi (formerly HMNZS Achilles) as HMNZS 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.
HMS Battleaxe was also used as a camera ship (off Malta).
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.
HMS Birmingham was used as a camera ship.
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.
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!"
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.
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.
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.
This was Michael Powell and 'Emeric Pressberger' 's most financially successful film.
Michael Powell later published a novel, "The Last Voyage of the Graf Spee", retelling the story mainly for children.
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.
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.