Revealing mistake: During the opening credits, as a crab descends past the periscope, the string attached to the crab is visible.
Continuity mistake: A sailor goes out on the luau covered deck to get his guitar, during an air raid. He lays down while a Zero strafes the deck hitting his guitar, which goes flying into the air toward the camera and lands about 10 feet from the sailor. In the next shot, the sailor kneels up and grabs his guitar which has appeared right next to him.
Other mistake: Close to when Tony Curtis and the nurse are going back to the pink sub, there is one scene where in the far background there are two objects moving on the water each creating a wake. It looks like someone is water skiing. A DVD will likely show this clearer.
Continuity mistake: After the air raid and the pink sub starts to submerge, there is a good shot of a Zero flying over the sub. You can get a good view of the bottom of the Zero and can see it doesn't have bombs or bomb racks. Yet, after it passes, there is a bomb explosion near the sub.
Factual error: Atop the desk in the Captain's stateroom is a model of a 5"/25 wet mount gun. The 5"/25 was designed for, and mounted on, U.S submarines; however, it was not introduced into service until 1944, and this is set at the start of World War 2.
Character mistake: At the end of the movie, when Tony Curtis goes aboard Sea Tiger, the word is passed, "Attention on deck." Since he is the captain, the proper announcement would be, "Sea Tiger arriving."
Factual error: When Chief Tostin and Major Heywood are arguing in the engine room, Tostin says "I'm a machinist's mate, not a laundry feeler!" Actually, his rating would have been motor machinist's mate (later changed to engineman); machinist's mates work with steam propulsion plants, not diesel engines.
Other mistake: During the sequence when the crew is working feverishly to get Sea Tiger repaired to leave Cavite, there are several shots of a first class petty officer welding a hand rail, a trivial job that would not be necessary for getting the submarine raised and underway.
Factual error: Lt. Holden and his men raid a warehouse on the night of 10 December 1941. When Holden is confronted by an MP, he explains his blackened face by saying it was a directive from Admiral Nimitz. However, at the time, Admiral Kimmel was in command of the Pacific Fleet. Nimitz was Chief of the Bureau of Navigation in Washington, and did not replace Kimmel until 17 December.
Suggested correction: Holden and men didn't raid the warehouse on December 10. The attack on the Sea Tiger occurred on December 10, and Holden wasn't part of the crew yet. He joined the crew after repairs were being made to the sub, so it is possible that by the time he received the transfer orders and got to where Sherman was stationed, Admiral Nimitz had already taken over.