Bird Identification: CLOSED: Can't find this duck in my guides, 2 by MartyJo

MartyJo wrote:
The weather was uncooperative and so was the duck. These aren't good pictures, but hopefully they wiil be enough for someone knowledgable to ID. Because of the overcast and the distance, I can't say for sure if the head was dk green or black or gray. The chest and flanks appeared to be white in the brief glimpses we got. the photo showing the back of the head clearly shows the band surrounding the neck but with a break in the back. The wings appear to be mottled. Any ideas?