In reply to Climbing Pieman:
Lovely Purple Sandpiper photo - in lighter winter plumage - that's pretty much a definitive ID shot, I can't see how you'd get a clearer shot to show the features.
And the Red-breasted Merganser, the males are obvious once you've realised what they are, females can be confused with female Goosanders, but I've never seen them in the same place (although there's bound to be places where they do co-exist).
RBMs tend more towards salt-water, Goosanders happier(?) on freshwater - I've actually had a couple of occasions now where I've not seen any Goosanders on my little bit of the Irwell, but today was compensated with great views of 10 Goldeneye, 4M, 6F, all in breeding plumage - they even stopped diving for a bit so I could actually count them confidently.