Someone should really look into creating a mod with that idea. Heck, I'd be surprised if there already isn't a mod like that. I remember a house mod that was built to look like it was underwater... crazy laggy though.
"Ninjas can't catch you if you're on FIRE" ^-- lol, I can't even begin to understand how that works --- Space for rent. Cantaloupes need not apply.
Off the coast of Hla Oad, there is an under water Daedric Ruin. If you swim down, you'll see a shattered statue. Talk to it's head(I can't remember if it is torn off the body or not), and it will send you on a quest. If you complete the quest, you will end up getting the sword Goldbrand.
--- If there were no God, there would be need to invent him. -Voltaire -Deus Ex
Why hasn't someone done a Bioshock mod for Morrowind or Oblivion? Especially Oblivion, since there are several mods to make underwater life so much more vibrant, and an underwater city mod, but no Bioshock.
Makes me sad. I'll even use a little frown. Watch. :(