So in this world, is it in anyway post apocalyptic [i]like[/i] Waterword. 
Is there slavery? Are there food and fresh water shortages? Are there people fighting over what little fertile land there is? I'm assuming because of the medieval tag that there are no guns, or electricity? Is there a religion, or any kind of cult within this world? Is the majority of civilization living life in the slums kind of way, while those with power are...not? 

Personally I am a fan of the movie Waterworld, and like the basic concept of it. Though it was in need of some heavy edits, and more realistic ideas. The Anime Gargantia on the verdurous planet is the only waterworld esqe anime I've seen...

I have some characters that I previously made for a few other adventure RP, and one that was made specifically for a water world RP. I would love to use one of them again, of course once they are edited to fit this RP.