The lightpaths were curved so that this method is not usable. I decided to use 40 randomly distributed spotlights in the viewing direction. I am not quit satisfied with that but due to my time consuming job I ran out of time so this has to work. No copy was intended, but due to the advanced level of my model I decided against dumping it. I hope you understand that.
Any comments are really welcome.
This picture is dedicated to my wife and my little boys for giving me the time to complete this work. That whale needs to eat more. Your diver is probably the least 'stiff' human I've seen so far in this competition. The spotlights really work in this scene as well. A good pic that captures the underwater feeling well.