There is a quilt called 'day at the lake' that is a look into a cross section of a lake..... applique in blocks that are then sewn together. I did this quilt several years ago (don't have a picture on my computer or would show you) and used darker blues as I got to the bottom of the lake, just like a real lake. Anyway, I google searched it and it came right up. Check this out.....
http://www.quiltknit.com/PT2028-Day-...e_p_12429.html