Hooded Mergansers (initially posted as Unknown Ducks)

My father and I went up to Carlos Avery on Sunday and when we saw these birds we thought we knew what they were, but upon closer inspection of the photo, I think we were wrong and now I'm not positive on the ID of these birds. Any help would be greatly appreciated.

Hooded Mergansers:


Thank you to all that responed to my request for help identifying these birds! I truly appreciate it.