Great image! I like it from both an artistic and technical standpoint. It is a good, sharp image, the exposure is right on and you have good highlight and shadow detail. The one thing that I really like is the way you have left some texture in the water. There are too many images that I see here of DeviantArt where the photographer has taken such a long exposure that all of the texture in the water is gone, having been replaced by a textureless, neutral mass. It's nice to see the tonality in the water has been saved, in spite of the long exposure. I thing that this really works well with the cloud patterns. The sky and water fit together very harmoniously.
The other thing that works really well is those large sub-surface rocks on the bottom right of thei image. The fact that we can still make them out means that there is some nice balance in the image. The overall cool tones work quite well, and whle they may be a touch cool for my taste, I can understand why you have used them.