10 years ago I was coming south on I5 from Redding to Sacramento, in the rain. As I was cruising along, I saw this really nice looking jet boat on the side of the road; it was a really pretty paint job and all the chrome...
But, there was no trailer or truck! Guess the same thing happened. There was nothing else there forth wich to judge what had happened, but I'm guessin stormy conditions(It was a VERY stormy/rainy Memorial Day Weekend) and incorrectly installed straps must have let the boat slip away...
About 15 years ago, I saw a boat come loose of a truck in a major intersection. The boat/trailer passed the guy, went through a shallow ditch, and into a field. To this day I do not know why it did not spin out when it went through the ditch. It appeared to survive with only minor hitch damge(ground off).