Trailer wheel lock? Does this exist?

Im 14 and my dad has a boat. We redid the whole trailer this winter and now we are ready to put the boat back on and finally go out! He has been talking about getting a lock for the trailer, because it sits in the driveway all day and someone could just take it. They sell locks that go around the wheel, but you could just take off that wheel and drive away. He said he had seen a lock like a parking boot, it goes around the wheel and covers at least 1 lug nut so the wheel cant be removed. Does this exist, if so, where do I find it? I have looked everywhere online!