There is an official bareboat certification available. It is available through the ASA. It requires you to do some pre-study at home of items ASA101 ASA103 and ASA104. The course materials cost about $100 per person.

The method followed by most to obtain this certification is to take a 10-night bareboat charter. In the first seven days, you have an ASA instructor on board. Some of this time must be on a monohull yacht. If you have rented a multihull, then often, the instructor has a small monohull sailboat available for this part at a small charge.
The instructor will cost about $250-300 per day plus food plus gratuity. You will also need to allow for a berth on your boat for him. After the seven days, you get your certification, then drop off the instructor and spend the next three days honing your skills and gaining confidence. This certification will allow you to bareboat anywhere and will let you go into areas that non-licensed skippers can’t. Once again, because of the perfect weather conditions and abundance of facilities, the British Virgin Islands is the best area to obtain a bareboat certification.