Any time I got into the water in TESIII: Morrowind- you can't very far and I always had this terrible fear of slaughterfish (this was near the beginning when I had no idea what I was doing).
My fear of Morrowind's aquatic areas was further increased when I first tried to swim across the Sea of Ghosts, only to be horrible slain by a dreugh lord.
Whenever I replay Morrowind nowadays I still try to avoid the water when I can.