About to commence 15th Moorings sail in a week. Over last 10 years, we have brought a motor bar lock for the engine and a cable with locks for the dinghy itself. For $100 or so, it's worth the peace of mind. Then we leave the locks for the next group instead of hauling them home. We avoid bringing valuables (especially jewelry)and electronics are well hidden, even when we are on the boat at night. The problem is rare in the BVI compared to down island, but sadly, it does exist so just play it safe and you'll likely never have a problem.