Continuity mistake: Early in the movie when Thomas falls overboard, John Smith ties a rope around his waist (00:02:56) and jumps in after him. Thomas is very far away from the ship (00:03:12). But when the men pull John and Thomas up, John is holding on to the rope with one hand and the end is left dangling (00:03:36). One of the men who pulled them up then coils the rope with a mere two coils (00:03:48), not nearly long enough to have reached Thomas while he was overboard. In the same scene, when we are viewing the men pulling John and Thomas up from above (00:03:38) there is no extra rope at their feet as there should have been for such a long rope.
Continuity mistake: When Max is running out of the school after successfully becoming cool. We see his friend with the orange mohawk at least twice. Once hanging from a statue, and another where he's reaching out from a school bus. These two shots are really close together so there is no way that he could have moved that quick.