An Ocean Planet is a planet whose entire surface is covered by very deep water, a single ocean hundreds of kilometers deep. This is very different from just being a wet and flooded terrestrial planet - an ocean planet could easily be 50% water by mass.
In the depths of those oceans, there may exist exotic forms of ice - ice formed not by cold, but by pressure.
History and Formation
Out beyond the snow line planets tend to be close to 50-50 ice and rock. However, there's evidence that planetary orbits shift and wander during the formation of a planetary system. So it's possible a planet might start out as a big ball of ice (either an ice giant (planet) or an ice dwarf (planet), then move close enough to it's sun to thaw out. The result would be an Ocean Planet.
If the Ocean Planet got especially close to it's sun, it would become a Hot Neptune.
Game and Story Use
- Here's a planet with great potential. It may have an atmosphere we can breathe, and no ends to what can be explored.
- However, it almost certainly has no islands or land mass, which may be a bit of a problem. Then again, if you can cross the void between the stars, you can probably build a floating city.