This Muscovy must have thought I had a snack, cause she was swimming for all she was worth straight toward me. That continuous focus really works. I was sitting on the ground with my knees bent, elbows perched on both knees, hand holding my 7D and 500 mm lens. That's the only way I can do it without a tripod.
7D * 500mm F/4L IS (800mm including crop factor)
ISO 400 * F/11 * 1/800 sec
Comments welcomed. Thanks for looking

Comments
4 comments* Why was there a halo on just that part of the image before edits? Could it have just been a lighter ripple in the water?
* There were no halos on other parts of the original posted image, so maybe the mentioned halo was not because of over sharpening?
* To correct it, I had to clone darker pixels over the white strip.
Would appreciate any other ideas from the knowledgable NPN audience