I like the perspective, the female looking smaller than the big guy. Good exposure, although Coot's bill can always use a bit of layer multiplying, the are so light. I'd crop some off the bottom since the reflection is not that great, right by the large water line. IMO it will make the image stronger.
Wonderful capture Marina. :) I agree about the crop, but I would crop this more into a panoramic format so off the top and the bottom. While the bills are very light, I don't think they are over the top, as long as your highlights are not flashing. Plenty details in the black plumage. I think you handled the tricky light very nicely. :)