Thanks for all the interesting comments. So what is the idea behind the dying planet and the missing seas. If you check my Etrakien thread you can read a bit about the background story to my universe.
The Archonts that created the worlds where seven to the number, so there are seven different worlds. When the big war between the humanoid empire that streched between the worlds and the archonts broke out it nearly brought the hole creation to an end. Some of the worlds (planets) suffered worse then others. One of the worlds that had to pay the greates toll was Arnoria. The result was that the oceans dissapeared, volcanos erupted, the earth cracked. So there are no rains in most of the parts of the world. The old seas are great grey desserts, usually called the great grey or the grey world. You can travel these areas but it is very dangerous. Strange lifeforms inhabit them and there is no food or water. The area is also very unstable and there are a lot of cracks into the borderlands where demons dwell. But you can get to ilands in the distant where you can find ruins with long forgotten secrets.

I hope this gives you some sort of explination.....in one sentence "it's all about magic" :-)