I've had several outboards stolen in the past. The only thing I found is to take it home. Not found a chain/ padlock to work yet. Welcome any advice on gear that does work to prevent theft (which doesnt involve painting the outboard bright pink)
With my dinghy, I used to anchor it just off the beach and have a spare line which i would run up the beach. Means you have less chance of things being nicked and saves dragging the dinghy up the beach and damaging it.