Down in Shelton in the 80's I watched a guy take his new aluminum boat and motor out for a test although he didn't clamp the motor on, just set it on the back. About the same time a big barge went by. Test drive went fine but as it was on the beach next to the ramp the waves from the barge hit. I looked over just in time to see the back of the boat pitch up and down, while the running engine then hit bottom and lifted it off the back and into the water. After some exhaust bubbles the guy looked over and saw what happened. I thought I would never quit laughing.