Plot hole: The Seaview's crew have a wild shootout aboard ship, and their bullets are seen to go all the way through a 6-inch-thick hatch door. Gee, you'd think that somewhere during their military training, somebody would have taught these guys why firing high velocity weapons on a submerged submarine is a really bad idea. (00:38:15)
Continuity mistake: During the battle a railing on a pirate ship falls off, only to be seen in the next shot intact, then missing in a subsequent shot.