Continuity mistake: The shots are badly mismatched when Demetrius saves the elderly slave about to fall from the rope. Their arms and legs shift positions multiple times between takes.
Continuity mistake: When the two men are carrying water up to their new cave home (via a home made elevator), one of the men is holding two buckets of water. In the shot where you can see the sea behind them, this man hands the second man a bucket of water, which he takes. In the very next shot, from inside the cave, the first man has both buckets and again hands the other man the bucket of water. (00:48:35)
Continuity mistake: After the fire in the captain's quarters everyone goes on deck for some fresh air. When they finally go below everyone has sweat soaked shirts except the psych doc who is perfectly dry.