Anyone have any ideas on how to lock or block out the fuel filler to keep some jackass from siphoning? My kid just got a new boat, had it parked in front of his house and some jerk hit him for about 17 gallons. I got to thinking that although we both usually keep them locked up, mine is in my driveway with about 40 gallons. Any type of insert or ?  What do you guys do. Thought about tying a dog in the boat over night, but I don't think the pugs would scare anyone off....If I happened to wake up and hear them I got the means to take care of business, but it is the waking up or being home all the time that does not work. So, ideas?

Dave