Re: Securing boat in my driveway
I use bicycle cable locks ran through each wheel to the frame of the trailer
I "used to" do the same,,, until I forgot to take the cable off one day while moving the boat/trailer to work on it. The cable snapped and was all wrapped up in the wheel. It wouldn't have stopped anyone trying to take off with the boat. I replaced it (after fixing the wheel bearing/seal) with some 5/16 chain.
To deter thieves I have 4 locks on the boat, 1- wheel locked to axle, 1- swing tongue chained back to trailer frame 2- locks through the swing tougue pin holes. If they want it bad enough they are still going to get it, but this will slow them down a bit, make it a less desirable target.
I have a coupler latch lock too, but it's really a toy. It wouldn't take but a couple minutes to hack through it with a hack saw, sawzall would take it off in 30 seconds. I use it more to keep kids from flipping the coupler latch then the trailer is attached to the truck, had them do that 1 time, was an interesting ride when it popped off on the freeway...

(&@$^#* neighbor hood delinquient)
Oh yeah, if you have a bolt on coupler, either weld it on or mangle the bolts so they can't remove the coupler easily. I saw a post from So Cal where the thief simply unbolted the locked coupler, then bolted on his and drove away.