Factual error: The second blackmail message from SPECTRE tells the British that they must drop the ransom diamonds in a container "off the coast of Burma, in the Mergui archipelago, latitude 20 degrees north, longitude 60 degrees east." Unfortunately, 20 N, 60 E is nowhere near Burma. It's right off the coast of Oman in the Arabian peninsula, all the way on the other side of India from Burma. The actual coordinates for the Mergui archipelago are approximately 13 N 97 E. I guess there wasn't a map handy....
Factual error: When Bond finds the hi-jacked sunken Vulcan, he swims into the aircraft and towards a door at the rear of the cockpit. In the real Vulcan there's no door. There is a full-width table with racks of "black boxes" where the bomb aimer and navigator sit.
Factual error: When Largo's henchman is hiding in Bond's shower, Bond turns on the hot water which scalds the villan. But scalding hot water is never the first which comes out of the hot faucet.
Factual error: Before the final fight when the soldiers parachute down, they are spread out over a long stretch of water (up to 1 km, it seems). It would take them a long time to swim together (and none of them are wearing the underwater jet as Bond is). Nevertheless they are all in one group minutes later.
Factual error: After the photo dive at Disco Volante, where Bond's air tanks are hit, he takes them off and leave them in the water. There is no air filled BCD attached to the tanks (which are quite heavy) but they float anyway.
Factual error: When the operation to plant the bombs is foiled, the Disco Volante casts off, pursued by two speed-boats and a destroyer. But how could the latter, as a large (and slow) battleship, approach the yacht without arousing suspicion?
Factual error: The Panamanian flag on the Disco Volante is upside down throughout the film. It flew in that configuration only in 1903.
Factual error: The Vulcan aircraft shown before and after the water landing has French markings. The Vulcan bomber was only flown by the British.
Suggested correction: The roundel is an RAF roundel type A.
