Strange stuff, this, cause wiyh the tweak files I get to access the scene_dat.txt, but there is nothing in it called "underwater", so I cant change underwaterfogend.
However, I changed the wateropacity to 18. I`ll hvae a go now to see if it worked.
Thanks againg, sombreros!
Edit: Nope, I propably need to change that fogend somehow. Starting to feel stupid here.