I lock my boat tight. Hatches dogged down, companionway locked, small passive vents for air, all exterior lockers locked. My marina lacks gates and any degree of full time security. A fellow there provides part-time lookout and we rely mainly on the fact he is always there and knows who's boats belong to whom and the faces that go with them.
An opportunistic thief could take a grab at my solar panels by cutting the wires but that's about it. Unless they can gain access below by cutting a lock free to grab my electronics and assorted hardware, they'll probably move on to the next boat. They'd honestly have more opportunity and greater privacy in the brokerage area.
All my stuff is insured anyway in the event of my boat being broken into or an enterprising scumbag breaking my locks free on the outboard and hoisting it away. I don't want the hassle and agony of dealing with a theft but I have coverage should it happen.
SV South Paw
2000 Hunter 340
South River, MD