When I was living aboard by little boat in a marina with public access, I came down to the boat around lunch time only to find a family of four in the cockpit eating lunch. Two small children. Taking the high road, I asked what they were doing and why they thought it was permissable to board some stranger's boat to have lunch.......

In the end, the two little kids got to see below and enjoyed the scale of the boat as little kids on a little boat would, the kids and I talked about other people's boats and such in a polite yet explanatory way. I hoped really I'd shown the parents the error of their ways and educated two potential future boaters.

Who knows? With anything really....