@chrisspoi: I have heard of the sky dome technique mentioned before in a 3Delight thread.
Part of what I was trying out in this scene was the mention that you can essentially emulate Blender Internal with Cycles by using a single Sun lamp, the background and setting all the ray bounces to zero. This does work and renders just as fast or even faster then Blender Internal in some cases. I had to turn up the bounces in this scene. I set all ray bounces to one and then turned up Bounces Max to two to make the water work correctly. The more reflections in your scene the more bounces you will need to see through them.
I wonder how the sky dome with an image map might impact performance? I’ll have to give it a try.
Here are a few more stills from this 450 frame animation, which is still rendering…day three.:o