From what I can tell, it seems that the underwater cautistics shaders have something like (vaguely similar...a bit) this:
applied to them and set to screen, and then the UV or texture is animated, so unless the effect (picture) has no visible seams around the seams of your model, as well as no seams around the seams of your model (confusing myself here, hang on).
\/ \/ \/ \/ \/ \/ \/
Also, with this approach to the lighting effect, wouldn't the best results be had from a top-down UV projection? As that would make the UV's line up better with the effect texture/shader?
I'm thinking if you did a uv projection from the side, the lighting effect would look like the light is coming from the side of the fish/dolphin/etc.
Am I right in this thinking?