This is a juvenile common loon fishing on the creek. Its feathers on the head and back are grayish brown, the undersides white. The bill is light gray, and the eyes dull to a deep reddish-brown. The juveniles have distinct whitish-gray tips of their feathers, which create a scalloped pattern. Common loons have superb diving skills. Their calls or vocalizations have a distinct, haunting quality.
In the photo its bill is horizontal but I've seen him point his bill upwards several times while swimming which is a good identifier of the loon.

Nikon P1000

crop, contrast adjust in Photoshop