Good perspective here Jonathan, and I like the droplets on the head. The colour of the water compliments the duck nicely. You have done well considering it looks very overcast.
I took the liberty of sharpening the bird and also reduced the luminosity of the water a bit to put more attention on the bird. There was a bit of sharpening halo in the posted jpeg, which looks a bit worse with the change in the water, but I think you get the idea. Nice perspective and pose here.
Jonathan -- I've been photographing divers a lot lately but I still don't have a golden eye...so I'm jealous. You did a nice job of catching one of these elusive birds in a good pose.