Between the two, I like the top (crop) better for a couple of reasons:
1) The horizon line isn't so centered.
2) That close-up stump/driftwood doesn't try to steal the glory.
but I do like a couple of things about the full-sized version as well.
1) I like the shoreline feel of the closer rocks.
2) You get the full reflection of the mountain, whereas the crop almost chops the reflection off a bit.
I'd LOVE to see a crop where that main mountain is moved over to the left a bit, and we get a bit more of the boat. It would still require the mountain reflection to be chopped off a bit, perhaps, but then it would look intentional rather than a "Wow, I just barely got that to fit" sort of feel. All in all, I'm envious of both the shot and the chance to be in the location to get the shot!!
(of course, all of my opinions are from the barely trained eye and are based on personal preference )
Here's another version of this view less the boat that shows more of the lake and the reflections in the water of the mountains.
View attachment 51717
As for the "rule of thirds", that is one rule I believe everyone should learn and then disregard at every opportunity they find. These so-called "rules" of composition were posited as suggestions in an effort to imitate the structure of classical oil paintings of the 18th century but have somehow made their way into being sacrosanct laws of photography. Photography is a medium of its own and while there is no problem with paying homage to the oil based landscapes, photography should never be held hostage to such a narrow frame of reference. I think in the very near future images in which the horizon is smack dab in the middle will begin looking unique and will be doted on as "new" and "fresh" much like the deadpan movement of the late 60's and 70's.