Continuity mistake: When discussing the broken EAM, Hunter is holding the message with two hands or one hand depending on the angle. (00:53:50)
Revealing mistake: When the men are waiting at the dock and when boarding the submarine, we see the wide shot of the submarine and the dock. The ocean is, however, incredibly calm despite there being torrential rain happening throughout the scene on the dock. While it's not seen, this would be from a rain machine not able to cover the entire location of the shot. (00:13:51 - 00:16:38)
Audio problem: When up on the top of the submarine, Ramsey says, "Hunter?" and Hunter replies, "Sir"; however, his mouth doesn't move. (00:17:00)
Continuity mistake: When Hunter is arguing with the captain, he is listing off points and raises his thumb and forefinger in points 1 and 2. When the shot changes, he has a closed fist. (00:57:00)
Chosen answer: The ship has a second antenna, but the radio is damaged during the torpedo attack. Therefore they have to fix it in order to use the backup antenna.