This last weekend I went up the hill to escape the heat. It was fairly crowded and lots of PWC's on the lake. A guy with a trailer carrying 2 of them, going a bit fast for the bumps, in the campground had his trailer come off the ball and it banged around the back of his pickup and bounced off the asphalt a couple of times before he could get stopped. I'd think that the coupler could have possibly been damaged. I'd heard him banging around the bumps the day earlier and thought, "WOW...you'd think he'd slow down on those".
Quite some time ago, someone had questioned crossing the safety chains, which is required by law in Ca. Had he done that, it may not have had the chance to do the damage that did occur. Safety chains can be too long, however a crossed chain will cradle the coupler if it comes off provided they are the correct length. Of course, #1...make sure you actually did couple the coupler and it's adjusted correctly. Just a few seconds of double checks could have prevented this. Don't be a dumb bunny like this guy was. Doug