Fixed the image above to the correct one. Note that the yellow is actually a lot stronger on my screen for some reason. I think it approaches a.. mustard-neon? Anyway.
Aside from the odd smokey yellow and sharpness, I feel the underwater view is just missing something important. It can't have looked this bad in vanilla.
.. except on my setup it's a lot more bright green, almost white near the edge of the water surface (looking in the distance - not straight above me ofc). Sadly my screenshots seem to be too dark for some reason, they don't really show that. Seeing as how that youtube account name is ENBDev, I'm going to assume that this is simply how things were meant to look with an ENB enabled, except that Serenity probably punched out the brightness of the green a bit too much by accident.
Once I get home I might look into manually changing the colours a bit to a darker brown or something. It must be possible somehow?