Of these two, I prefer the second to the first. There are only two things going on here: silhouetted hills (black) and moon-lit sky and river (with light), and I therefore feel there is just too much of the black-only part in the vertical frame. Makes the eye race round the black looking for a "light-anchor" (well, that happened to my eyes, and I can only speak for myself here, of course).
And this does not happen with the second photo.
Most unfortunately, though, precisely this second photo seems to be suffering from compression (through loading it up to the web) more ... have you compressed them well enough before you loaded them or have you let Photobucket do the compression for you? They will BUTCHER your work - this has been topic in two other threads on here within the last two days of two other members whose photos suffered similarly).