It's a shame that there aren't more Waterworld style post-apoc movies and novels. I actually had quite a bit of fun with that movie.
"Fallout 4: A Waterworld Style Adventure". All you need are the "Smokers", and Dennis Hopper, and you might very well have a really decent game!
Deacon: "If you'll notice the arterial nature of the blood coming from the hole in my head, you can assume that we're all having a real lousy day".
*Actually, there was a "Waterworld" game released by Interplay, for PC.*