We were tied out last summer. Around 8:00a, my wife said come look at this. There was a fisherman about 3 feet off the back of my boat. I fired up the engines, put them in gear, and prop washed him about 50 feet. He got the point.
When I had to pull my houseboat last fall for other reasons, my port side had about 20 ft of line wrapped behind the prop. We have see people's canvas torn from lures.