As far as I know, this is a female Greater Scaup (I could be wrong though because I'm terrible at ID'ing waterbird species ). While I was photographing the Grebe from my previous post, I noticed this small duck swimming towards me out of the corner of my eye. I only had a couple of seconds to rack focus to MFD and shoot a couple of frames without changing my settings before it too disappeared underwater (I wish I was able to stop down). Very minimal NR was applied in PS (almost negligible). This version is heavily compressed to fit within the site's upload regulation.
Camera - Nikon D850
Focal Length - 700mm
Aperture - f/8
Shutter Speed - 1/400s
ISO - 900
Handheld
Manual, Auto ISO
Crop - 75% of full-frame