Continuity mistake: On the airplane, the shark bites off April's hand at about the wrist area, but when Fin pulls the gun in April's hand out of the dead shark, the severed limb is an entire arm up to the elbow.
Continuity mistake: When the 7 train comes to an emergency stop, the tiled wall beside the tracks read Grand Central, but on the platform the pillars read 96 Street.
Continuity mistake: After Fin and the others exit the subway there's a baby shark stuck onto Fin's denim jacket which results in a large tear in the material, but that large tear in Fin's jacket vanishes and instead shows just a few small marks thereafter.
Continuity mistake: At the start, Fin and April are seated over the aircraft's wing and the cockpit is located ahead of them on the same deck, but in the exterior shots of the aircraft the flight deck's location is on the upper level.
Continuity mistake: While on the 7 train, when Fin looks out the last car's window and sees the flooding and oncoming sharks, as he shouts, "We're in trouble!" in the closeup we see the door has certain stickers and markings and there's an advertising poster on the wall, but when it cuts to the wide shot it's all changed.
Continuity mistake: When April's lying on the gurney, just as she's wheeled through the doorway it cuts to the closeup as the nurse turns to block Fin from entering the ER, and behind the nurse we see the gurney still being turned and wheeled into the room, but April has vanished.
Continuity mistake: After April sneaks out of her hospital room, it cuts to the taxi with Fin, and the cab pulls over to the curb at the corner of Broadway and West 48, but in the closeups they're in an entirely different area - note all the buildings, then in the wide shot they're back on Broadway.
Continuity mistake: When the girls are leaving the Statue of Liberty the first outside view of the ferry is white and says "N.Y. Waterways." When they show the second outside view it is a red ferry with no title.