Lovely picture, the sky is so dramatic. To my eyes it might have looked a bit better if you had cropped a bit more off either the right or left side so that the main emphasis of the picture didn't end up so centered.
ohhh!! I love the dramatic sky and composition too. It is one of my favourites. Maybe could be improved with a swan nearer on the foreground. Otherwise, excellent work.
Ah, a competent image at last. Good detailing, good tonal work, perhaps a pity the swans weren't a touch more organised for you. Even beyond the challenge idea, I think it lacks foreground elements - oh for a swan to wander closer to camera. 6