Attached Link: Underground Lake

Hello everybody peeps,

This is a quick rendering of a Vue scene I'm working on. It's a recreation of Lake Melissani in Kefalonia. In the next post down, I've posted a photo I took when I visited the real thing.

You'll immediately see that the main difference is the cave walls. And that's pretty much what I'm posting here for... how can I better recreate that sedimentary stepped look on the walls?