In the video, the aircraft descends on a shallow run and is about to land in a seemingly calm bay but then pulls up abruptly as the surfacing whale blows a geyser of spray up over the plane's windshield.
"The guy I was with on the dock looked at me and said, 'Tell me you got that?'," Hamm said.
"I played it back and there was the plane and the whale ... These guys who fly in Alaska, let me tell you, they are good."
The clip, posted by Hamm on Youtube under the title "Whale v. Pontoon Plane," has received more than 170,000 views in less than a week.