My girlfriend and I chartered a boat out of Road Town, Tortola for a week last September. The mooring buoys at the dive sites are color coded to indicate their intended use. You are supposed to only use the white buoys, which are intended for non-commercial use. The yellow buoys are reserved for commercial dive operations. We found that most of the dive sites that were listed in our guide book only had yellow buoys, meaning we were not supposed to use them. At the time of year we were there very few dive shops were operating, so we just tied up to the commercial buoys and risked getting a ticket. We never had a problem, but you might not be so lucky when you go.
You should make the Wreck of the Rhone a priority. It is one of the most popular dives in the BVI's, and is worth doing. It is popular enough that there were plenty of white buoys to moor on.
Another cool dive was The Playground, where we saw two eagle rays and a nurse shark. However, I think this was one of the sites that only had yellow buoys.
The wreck of the Chikuzen sounds like a great dive, but we couldn't find it. If you can get GPS coordinates ahead of time that would be a huge help.