Canvasbacks flying in syncron.
I have managed to take two shots (and more in between), one with the wings up and one with the wings down.
They usually fly far from shore but three of them came close enough, well sort of.
Canon MIII
Canon 500 f4.0 L IS plus 1.4X Canon TC
Manual setting at ISO 400 f 5.6 1/1250 sec
Hand held
Great flight shot. I like the wing pose and the fact that both ducks have the same. Beautiful light and great sharpness.
I only wish there was a little space between them as Jeff already wrote.