These oceanic worlds are rockier than their tropical counterparts, and have unique island formations. Some possess deep underwater canyons, volcanic expanses or corrupted isles covered in strange toxic water. You'll find coral of various sorts here, all of which are handy when extracting for resources.
Codex description Edit
These oceans are vastly more rocky and unstable than typical water planets. They generally lack tropical islands, but if you love rocky terrain and coral reefs they might be right up your alley.