For most of you guys this is nothing new, but for clueless noobs like me, I thought it was an interesting discovery. Personally, I felt the default water had an almost "metallic" look to it. (didn't really like it) To me, this setting gives the water a little more realistic look. It's personal taste, of course...
Here's a before/after screenie, and the settings....
BEFORE:
AFTER:
Settings: