(My two bits of wisdom): If no one in your group has ever participated in this type of adventure, nor visited the British Virgin Islands, then I would suggest a hired skipper would be very beneficial for both the operation of the boat as well as your guide to the islands. If someone in your group has indeed participated in this type of adventure in the BVIs or similar location, then it depends on their skills at operating a boat. You apparently do not know the answer, but you do perhaps know if they are normally either careless and/or irresponsible (say when diving their cars). The British Virgin Islands is considered a 'skill level one' sailing destination. You are never far from land, hardly more than several miles, simply 'bumping' from island to island (you will not be in the open ocean with no land in sight). If your friends are responsible individuals, you should be fine. Again, nothing wrong with having a local skipper, just the extra expense and giving up space on your boat. Catamarans are much easier to manage and operate (perhaps only my opinion) sort of like a 'party barge' although more expensive than mono-hulls.