Back in the 1980's, Dad docked his 17 ' Thompson at a friends dock, and stored the friend's boat in the winter. They called it even, and Dad always helped get the dock out and the boats in and out of the water in the spring and fall.
It was spring time, and Bill and Dad were launching Dad's boat. They backed down the Alton Bay launch, Dad in the boat. He started it up, let it run for a few minutes, and went to back off the trailer. They realized that they had not unhooked the winch hook, nor the safety hook. They got the winch hook off ok, but the safety hook as really stuck in their.
They decided that they need a pry bar of some sort, and felt a jack handle would do the trick. Bill's Ford Bronco had the jack and handle under the hood, and Bill looked in vehicle, saw the two handles -- one for the hood, and the other for the emergency brake-- and grabbed what he thought was the hood release. WRONG
.
Boat, trailer, and Bronco headed down the ramp. Dad slammed the gear shift in forward, and was able to stop the package just before it went off the concrete pad of the launch ramp. Some wonderful onlookers got very wet and very cold wading into the water to help get the whole rig out.
Someplace I have a newspaper article about it. If I can find it, I will scan it and post it. Stuff can happen to even seasoned boaters. It just takes one careless move. I guess that's why they make checklists
.