Is there a texture somewhere that affects the 'fogginess' and color of what you see underwater, or is this generated by the game like the portal texture?
Thanks! It was misc/water.png, and it supports transparency. I replaced it with a 75% transparent blue, and even though the water still gets darker the deeper you go (which is perfectly fine), it is now much easier to actually see underwater because all of those stray pixels in the original texture are gone.
I also found that the misc/vignette.png file is the texture that is applied to your field of view when you are in darkness (it darkens the edges of the screen and almost gives you a kind of tunnel vision). Replacing this with an empty, transparent image removes this effect and improves visibility.
Tronic Revamped — Minimalist texture pack
I also found that the misc/vignette.png file is the texture that is applied to your field of view when you are in darkness (it darkens the edges of the screen and almost gives you a kind of tunnel vision). Replacing this with an empty, transparent image removes this effect and improves visibility.
Tronic Revamped — Minimalist texture pack