When I bought my sanger hydro or better known as "project lost cause" the boat would not come off of the trailer at the launch ramp. So when we finally got it tom break free from the trailer, she started going under but with no signs of water in the boat. Well come to find out, since it had a floor in it that was sealed, the guy installed these seats out of jegs that I was ripping out anyway once I started the restoration. Well he screwed the seats in with 4 inch wood screws. Yes that is right folks right through the bottom of the hull. Not to mention the few holes that were in the bottom of the boat that were covered by the trailer bunks. So boat filled with water. Nothing I could do but drill holes in the stringer that separated the engine compartment from the air pocket under the floor to get the water out. Point of the story is - I bought the boat anyway. I wanted a resto project and something different from a family boat. But yes it sunk right off the trailer.