I'm hoping for underwater caves. Islands FAR out in the ocean, as in Morrowind, with hidden and cool stuff on them.
Forgotten and ancient ruins under the water.
Lots of small islands, a kinda big island or two would be nice.
SEA MONSTERS. BIG WAVES.
SHIPS ACTUALLY MOVING.
I love the ocean. The ocean experience in Oblivion was a disappointment in my opinion.