Personally I see minimal usefulness of the underwater blur effects in a submarine sim. I know it's for 100% immersion, but no real WWII captain went outside underwater to see his own boat anyway.
I use the underwater views it to admire the graphical beauty of the boats & torps speeding through water and of ships sinking to the abyss. Sounds lame, but I love the ocean and it gives me a thrill. I understand why it's been implemented, but in this case I'd leave it off.
Awesome megamod, it seems much faster than individual mods put together.