Perhaps a cosmetic change to oceans? Set them on fire.. maybe make them burn ships?![]()
Hell oceans have been discussed in the past. I believe the main problem involving them was not changing the ocean tiles, but changing the rivers. It is difficult, if not impossible, to have rivers change color, as they are not tiles.
A really nice graphic for a corrupted ocean was made for another project. It had a green, brackish color, if I recall correctly. Someone pointed out it would work well for hell ocean. But it would look odd without changing rivers.
Aye - the green one is really good, as is the purple. I figured that keeping it blue, but noticeably darker would let me get away with the rivers, but the straight edges stood out too much.
I think Sevon05's world piece mod has 'Deep Ocean' which is a darker ocean. It seems to blend quite nicely, although you would also need a darker coast. Another thing that might be ok is a subtle churning or boiling particle effect, although you would have to watch the framerate.
For low framerate you could aim for something "tar-like" which will just have an occasional bubble-plop.
Aye - the green one is really good, as is the purple. I figured that keeping it blue, but noticeably darker would let me get away with the rivers, but the straight edges stood out too much.