What kind of setup do you suggest for the lighting? I really don't know much about it. At the moment the caustics are coming from a spot light, and the sun is provided by a directional light.
Before adding particles, fog and so on, sort the lighting out. The added atmospherics are the cause of the murk at the moment.
Thanks a lot for the help, I think you're right about the various caustic effects. I never thought of looking at finding nemo for reference.
There's something ineffable that was lost between the last one and the one you just did. It's such a fine balance. I think, if you'll allow me, this is how I see some of what might help...
I think the ground webs were better in the previous. they're lost now. Too nice a detail to lose. I think what needs to be done is a bright light through a murkier mix of water. The one glaring thing that's speaking to me is the lion itself being too clear (poppy) over all, even though I think you're going for DOF.
God rays are too "washy" I think when compared to the previous version. They should be grainier vs brushy and dense. Also, a little too uniform coming from a center, above-water point of origin throws off the dynamics of the shot. I would angle them in at a diagonal.
What I really think would benefit are some floating fg particles, racked with a few picking up the sparkle (see Finding Nemo- I know it's cartoony, but the lighting levels in that film would really assist.)
I know I'm not a Maya pro yet, but artistically I have some BG in those things traditionally and that would be my input. Its a very tight piece. I think you can really take it to the next level.
Hope that helps. What are you using for ref btw?