I just want the water-physics to be realistic, so at the very least I could throw something in the water and stand on it--then use some kind of magic or something to propel myself.
i dont think thats magic, just bad burritos
the behind the scenes video seems to be the most detailed map of skyrim i could find but it apears that (depending on scale) there are 5 lakes 4 of wich are connected by rivers. Maybe while in a lake you could sail freely and when you want to travel to a different lake you could go to the mouth of the river that is in the directio of the lake you would like to travel to.
hey it may work
edit: and that does not take into account the whole northern coast