Hi scalem
mate when i insured my boat they ask me if the boat was in the front yard or the rear as well as if in rear yard is the gates lock type if in front yard is boat chain to fence, tree or special made concrete footing
this spun me out but hey answered the question chain in through the wheels around the axle and through the other side of wheel and pad locked to tree or fence pole as it is in front yard so long as they can not just walk straight in hook up trailer and drive away is what they are looking for or for extra safety your can go to the trouble of running a chain and pad lock through the eye on the bow down to the trailer and pad lock it as well or place one of those trailer tow bar locks on
but the main thing is they are loking for is that the theif can not just drive away without some form or stuffing around or like a mate did once he had co-jo in his front yard
but as i stated to the insurance company if someone wants your boat bad enough they will just cut the chain or pad lock
response to this was as long as you have made the effort to secure your vessel and trailer no problems
cheers
Steve