I know in skyrim we will only have one northerly coast of sea available, but i think the it is an aspect that hasn't been taken advantage of in previous ES games. To fit in with the supposed savage aesthetic of skyrim there should be big, decapitating waves that would happen during violent storms that could change very suddenly into a calm song of the sea, and vice-versa, and if you are daring to wade into the rough sea's (or indeed dragged in) that should be a good chance of you drowning. Boats, both merchant and private should also be either passing through the docks (if there is one in the coastal cities) and sailing past the skyrim coast, which opens up the opportunity to hijack, stove away or indeed join in the plundering, not to mention being able to charter a ship and search for sunken treasure.
If you have any further idea's/loving compliments please share them.
and i meant to write mutilation! if there is an spellchecker savvy admins around if you could correct that I'd appreciate it.