Always
A big grizzly moves in on two guys in the woods. One guy starts running. The other yells, "Dude, you can't outrun a bear." The reply, "I don't have to outrun the bear, I only have to outrun YOU." As you say, most thefts are probably crimes of opportunity. No lock will defeat a determined thief but if yours is secure and the next one over isn't, most thieves will move past yours. It's the same rationale I use when using the club on my car. The system we use works well for us. I bought a long vinyl-coated cable (about 25') from Home Depot. I attach it to the outboard by looping it through itself (theres a loop on each end.) I then run it through the gas tank handle, over the bow and through the towing ring. This secures all the expensive stuff. The rest gets coiled up with two velro wraps and lays on the floor in the bow. At night I just uncoil the cable, bring it aboard and lock it to something that can't be reached easily from outside the boat, like a cockpit padeye. It stays set up ready to use and otherwise out of the way until it's time to "decommision" the dink. When we leave it at a dinghy dock I can take it to a cleat, pole, whatever and lock it. When at a busy dinghy dock like at Key West where we might have to "double park" I can still take the cable over dinghies parked inside me and a lock it. Theres enough length in the cable that the inside dink can push ours aside when leaving. There's also enough length in the cable that I can often get to a tree or pole or something. It's nothing that a good pair of bolt cutters couldn't defeat but most thieves don't carry around tools. It's enough insurance that we sleep better on the hook and feel better when leaving it to explore. We also have a short cable that we use to secure the outboard and demounted wheel when we're in our home slip. I've been ripped off several times. EVERY time it was someone just looking for a joyride or took it because it was "just sitting there."
