Revealing mistake: When the TVs explode, the glass is very fake and "cardboardy".
Revealing mistake: Madison is wearing jeans as she walks towards the group of tourists although she's supposed to be naked.
Revealing mistake: When Allen is in the park and drives backwards to avoid the MPs, there's a closeup where the pigeons fly backwards, revealing the angle is the previous one with the birds taking off but played backwards.
Revealing mistake: When Hanks drives through the city escaping form the MPs, the guy driving is a very obvious stuntman.
Answer: The sea hag gives Madison a set of instructions she has to carry out, and tells her that she can only survive out of the ocean for six days. She also tells her she has to wet her tail every day, which is why Madison is seen in the bathtub.
raywest ★
That's why she took a bath that night and got her legs wet turning them into fins.