I have to agree with all the positive comments on your image. Having looked at it cropped, I have no opinions either way about the foreground.
I think that the extra brightness around the shoreline is probably a consequence of a difference in the degree of agitation of the water surface at the edges. In the open water there would be ripples, but less overall irregularities. There, some of the water surface would be at a greater angle and would be reflecting a different part of the sky.
John