The capture itself is really good, as awarded by the judges at Better Photo.com.
One thing you could do to make it better, but still believable, is to capture clouds with more dimension --more dark grays and lighter shades. Then carefully selected the background of this image with a pen tool or Wacom tablet and insert the new, more dynamic sky, into this background. Of course, the lighting direction has to be correct.
I learned to do this with Jim Zuckerman's class, Creative Techniques, at BetterPhoto.com and it really makes a huge difference in the creativity of our work!
Digital photography offers a whole new world of possibilities even when the lighting is more overcast than we would prefer.
In film photography, I used to manipulate the negatives in the darkroom to bring out more detail, or to sandwich negatives. But, with digital similiar techniques can be done using Photoshop and the techniques of the Master Photographers.
The only thing that may present a problem with this technique is the reflection in the water. If you learn the technique from Jim, ask him about this?
I loved capturing images of the Sweden's coast and its islands. They reminded me of our summer camp in Northern Maine, USA, but Scandinavia is far cleaner and well kept than much of the U.S.
I think you did a wonderful job with the capture itself...and perhaps there is a way to enhance the sky in a believable fashion.