Continuity mistake: In the barn dance scene Gideon is doing flips on the sawhorse. His shirt becomes untucked and then retucked between flips.
Continuity mistake: When Ned Land dives into the ocean to save Nemo from the giant squid, his knife is in his hand. After Ned reaches Nemo, he then draws the knife from its sheath.
Continuity mistake: When Richard Denning and Richard Carlson approach the boat ladder coming back from their first dive in the Black Lagoon, you can see the net hanging underwater just to their right. It already has the huge torn hole that is in it when they hoist it up after the creature is caught for a moment in a later scene.
Continuity mistake: When Marilyn Monroe tries to untie the raft and Robert Mitchum can just catch the rope it the river flows from left to right. Later, when they take off again together, the river flows from right to left.
Continuity mistake: Shichiroji throws a spear out the door of Rikichi's hut in anger, it lands obviously in parallel with the door. Later, after Kikuchiyo's outburst he runs outside and picks the spear up, however it's now laying sideways compared to the door.
Continuity mistake: As the crippled airliner nears the coast, John Wayne slips his life jacket over his head, then provides one for another crew member. He then turns toward the cockpit, and his life jacket has magically threaded itself around his waist, and tied itself in place.
Continuity mistake: In the scene set during the King Arthur and the Round Table era we see the end of a battle scene. The camera pans in on some dead enemy and we see a man in a helmet face down. The scene then changes but comes straight back to the dead enemy. The man in the helmet has turned away as if to survey the scene before him. Within a second he turns his head back to the original "dead" position. (01:19:30)
Continuity mistake: The two workers are being dismissed by their boss after their 'too zealant' repairs of the streetcar. Shot from behind when he stops them as they walk away, you can see him place his right hand flat on the desk, directly on the wood. Next shot and his hand is in a different position and on the papers. (00:05:30)