I leave my boat on the beach in SC. I've had the boat turned over, my porthole covers used as frisbees, the boat set on its wheels and dragged into the water at low tide and left, you name it its happened. I take everything that can be removed off the boat, cover the tramp with sand and tie the wings up against the sidestays. They still don't leave it alone. I now have the local authorities get anyone thats on the boat off at night, including me. This year I have had no problems with the boat, even over the 4th of July.
A couple of cinder blocks buried 5' in the sand and a chain / padlock will at least keep the boat from being relocated easily. That worked great for the boat but my trailer was stolen from where it was stored at my brother's house two blocks away. We should have chained that one up too.
