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: 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: 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 Vulcan aircraft shown before and after the water landing has French markings. The Vulcan bomber was only flown by the British.