Wouldn't underwater fighting be difficult in this type of game. Underwater was really more about exploration to me, and the simple underwater enemies(mud crab, slaughter fish) were there just so it wasn't completely dead down there. Aside from the fish those other too I fought on land more often. Unless they made some changes to swimming mechanics I think it would be too difficult to fight a sea dragon unless it stayed still. Maybe if it was a partial underwater fight it would be possible, but otherwise I don't think it would work. Maybe something like a shark or squid would be okay?
If you could look 360
o Then I don't see why it would be a problem. All you
really need is water breathing. I suppose a kraken could grab you from levitating to the bottom of the ocean causing the water breathing potions essential! I don't know about you, but picturing myself enjoying the view in a peaceful stroll a few feet above the waters of Skyrim and then svcked to the dark, cold, depths of the ocean would cause me to [censored] bricks!