I have... so many other things to upload on here. It's not even funny. But this one, definitely needed to come first.
I did this about a month ago (though now looking back at it I want to work more on it). It was a concept I thought up for my own game idea. I wanted to create a habitat suitable for aliens. And I wanted to capture the way light hits the seafloor.
Edit: Needed to state the sources/references used-- various photographs via google, picasa, and flickr for kelp forests & deep underwater lighting. (Example: [link]
Which by the way you guys should check out.