I used to keep a wood splitter chained and locked in a shed. Someone wanted it so he cut the gate lock, cut the chain lock and stole the splitter and the chain. At least he didn't leave the gate open so the cows got out.
I leave my Champion with both depth finders, 18 rods and reels, and a host of various baits sitting in campgrounds all over the place from March to December. The only protection it has is a canvas boat cover. I just keep a good insurance policy. My belief is that if a thief wants it he will get it.
I do keep a little something in the camper in case someone wants to visit in the night (40 cal. semiauto.).