Aquatica is a large world of my creation, that is mostly water with little land. I created her with the D&D 3.0 Worldbuilder Handbook.
Her past has seen hundreds of years of Mage Wars and chaotic upheavals, that has changed the face of the planet in many ways and the lives of most of her inhabitants.
The regions vary from sub-arctic to super-tropical, creating strong seasonal variations. Everything from the weather, dimensional shift areas, mutations, and a variety of other ills.
All these problems started when a group of extra-planar races discovered Aquatica, she was a primitive world at this time, with rich deposits of many natural resources. The two races in charge soon began to disagree on how to treat the slave labor. [The slaves were the ancestors of humans, that had been artificially evolved by magic and bio-organic technology]. The Atlanteans and Astral Elves disagreements were on many things, including: whether magic or psionics were better, the experimentation, evolution and treatment of subjugated races; among others.