I would go back next week, park in the SAME spot and hide in the brush. When they start their **** I would be ready to unload my shotgun on their azz! They would be the one with a busted boat, motor and a few pellet wounds. This is a sad world we live in today. When I was growing up no one had to lock a camp, my grandfather would live is flat boat tide up on the river bank for weeks and NEVER worried one time about someone bothering anything.
This, but take some pics and give them to the Wardens.