GETTING THERE
This is my trip report from three trips to Tortola, British Virgin Islands (BVI). I was there in January, 1994, July 1995, and January 1995.
Tortola is one of the BVI and is located about 30 minutes from San Juan Puerto Rico by airplane. American Airlines flies there in small planes because the airport on Beef Island (adjacent to Tortola) has a rather small runway. Tortola is 95% mountains and the roads go up and down at seemingly 45 degree angles. However, I would recommend renting a jeep as that is the easiest way to travel on the island even though it is only about 20 miles from end to end.
Diving in Tortola
Dive operators include Underwater Safaris and Baskin-in-the-Sun which is under new ownership since a year ago. In talking to the instructors, many came to Baskin from Underwater Safaris because they too have a new owner and he does not understand how to be successful in the dive business. I was VERY happy with Baskin the first two trips to Tortola but was disenchanted the last time because they have turned the operations into a numbers game rather than depending on repeat business. This is sad because the instructors employed by the operation are quite good and very knowledgeable and with the new philosophy, their ability to give good service to guests is diminished. They have two locations: West End where I went, and Road Town. Road Town is primarily used to service the Prospect Reef Hotel while West End Services the smaller hotels like Sugar Mill and Long Bay Beach Hotel. There is a third dive operator on the island as well. 
Baskin's dive boats are geared to handle up to 14 divers comfortably but most days we had significantly fewer and one day had only two, myself and an instructor. Baskin also has a much larger dive boat, Narcosis Two that is used on long trips, e.g. to the Chikuzin or for large groups. This boat is out of the Road Town location only.
I often prefer to go off with another person rather than staying with the group. Baskin allows this once they see how you dive, how much air you use, and how your buoyancy is controlled. I was even allowed (on a shallow, calm dive) to go off by myself without a buddy. (Horrors, I know. I came up after about an hour with 1300 PSI - actually I solo dive all the time when allowed) Dive sites from West End are about a half hour boat ride in a protected five mile wide channel that feels like open water without the waves. Dive sites from Road Town would be about 15 minutes less. There are usually more divers from the Road Town location, however and sometimes the number on a boat is substantial.
Arrow Crab
The dive package includes three boat dives per day. Shore diving is not really available. Night dives are available but extra. Virtually all dives sites have significant fish and coral populations. Some dive sites have greater chance of large pelagics. On this trip, for the first time, I was chased out of the water twice by sharks (7 foot bull sharks). However this was on the Atlantic side of Tortola which is rarely dived. Fish population is diverse and typical of the Caribbean but I saw a frog fish which is rare, a snake eel which is rare, and of course the standard assortment of rays and eels of different varieties. Angels include Queen, Gray, French, Rock Beauties. Many varieties of Parrotfish, tangs, damsels, chromis, etc.
Food on Tortola is a bit "pricey". The most expensive dinner was$38/person but it was also the absolute best (Sugar Mill); this is a must do restaurant. The Apple Restaurant had good conch and fish, Pussers had good deli food. Night life on Tortola is a bit sparse. What there is of it seems to exist in Cane Garden Bay on the North Side of the island.
Spotted Moray Eel
Costs vary depending on where you stay. The MOST expensive is Long Bay Beach Resort which has a gorgeous but not very functional beach. Nearly as expensive is Sugar Mill which is my current favorite if we ever return to Tortola. Both have a meal package but I would not recommend that in the case of Long Bay Beach Resort if you are willing to go around to other restaurants. Things are cheaper in the off season and having been there on and off season, there does not seem to be a difference. During the summer there may be less winds so the Atlantic Side is occasionally able to be dived and the diving is a bit more exciting on this side. In general, there may also be fewer fewer people. I stayed at Long Bay Beach Resort and found that quite satisfactory but the service and people at Sugar Mill are much better.
http://www.underwaterphotos.com/BVI.htm
