Revealing mistake: During the naval battle, after an underwater shot of a man being eaten by a shark, check the poop deck on the left, and you'll notice a bulky floor with wrinkles around where people fighting and falling bounce on, revealing a tarp hiding a safety mat.
Revealing mistake: When Constance's baby is taken out of the water, she is an obvious doll who doesn't wink or move a single inch. She even cries, but her mouth doesn't move. In some shots, she is replaced by a real baby.
Revealing mistake: In the first scene, they skid around a corner; there are many other skid marks on the same corner from previous takes.