Bosherston Aythya....

As Paul suggests, the mix of features makes it difficult to name this bird with any certainty as either a Scaup or Tufted Duck, and I certainly agree that the features Paul noted rule out a true Scaup, so I guess that the bird must be either a hybrid or abberant Tufted .  Either way, it is nice to have a local Long-tailed Duck, it's been a while...