Visible crew/equipment: When the boy takes the boat out for a ride by himself and is riding it around in circles, you can clearly see the helicopter's shadow in the center of the circle.
Great sites
Mistakes
When the boy is dropped off at the cabin, Ethel's sweater is zipped down. It goes to a close-up of her and the zipper is up. In the next shot, the zipper is down again. See more...
On Golden Pond mistakes
Continuity: Watch kid drive Norman's power boat. He is at the steering wheel, and appears at the left and right side of the boat in the same scene.
Revealing: When Norman and Billy crash the boat, the side panel rips off of it before they hit the rock.