The problem Waterworld had is it was written to be Mad Max on water, a low budget action movie. The Kevin Costner got his hands on it, filmed in the ocean (even after Spielberg warned that would be a huge mistake), and spent $175 million bucks making it. If you watch it as a low budget Mad Max on water it’s a fine little movie. $175 million is supposed to buy more than an Mad Max ripoff though.
I have not read the book and I am just curious as to how the movie could have been improved upon?