Great job! Love the glassiness of the water, and the sense that I better get indoors before it gets too dark. It seems busy on the opposite shore, and emits a feeling of solitude on my side. I'm not a big fan of the technique that creates the look around the foreground rocks, making it appear like fog. Just a bit too 'Lord of the Rings' to me. But overall, a very nice shot. However, a water shot, or even a shoreline shot, does not always mean 'beach' in my opinion. And meeting the challenge, to me, is the first and most important thing, if that isn't done, then anything else is unimportant. Doesn't mean it's not a beautiful and creative shot, because in this case, it absolutely is! I do love it! I went back and forth on how to score your pic, but I do vote low for those that I don't think meet the challenge, so to be consistant, I am voting this lower than I want for the reasons stated above.
Nice long exposure - reminiscent of (showing my age here) Brigadoon, the mythical town that appears once every 200 years (according to Hollywood!!) Composition very good.