Getting to St. Vincent was formerly relatively difficult for the Caribbean and could not be done in a single day. But with the opening up of American Eagle flights from San Juan, Puerto Rico, it is now relatively easy; it is now simply a two hour flight from San Juan to St. Vincent. For most of the year this flight goes once per day but during the holiday season, this is increased to twice per day. The St. Vincent airport is small and scenic but functional and is five minutes by taxicab from the hotels convenient to the dive shop. It is likely that customs will make you open one bag for them to peruse the contents but the examination is cursory and in my case, they let me pick the bag. Once you have gone through customs, cabs are readily available for transport.
Although the dive
operation is small by some standards, it has four boats suitable for diving,
four dive masters/instructors, and a small selection of rental dive equipment.
The dive boats are small and handle six divers fairly well but more than six
would be pushing things a bit. Fortunately there is no attempt to pack the boats
and groups are split for customer satisfaction once they exceed six. There also
is a pretty good attempt to group divers by skill level and interests but most
of the divers during the period I was diving period were fairly inexperienced.
Diving is with steel 72's or aluminum 80's depending on your preference but
you must express that preference as the default without discussion is the steel
72.
On your first dive, they will make you descend using the anchor line (or mooring
line since almost all sites have moorings) to make sure you know how to dive
and this is irrespective of experience or certification level. Don't fight it
as it will make no difference but after they know you, you can dive according
to your skill level with the caveat that you cannot stay down a lot longer than
the group. Most dives were 60-65 minutes and the average maximum depth was 90
feet or so (but some dive sites have nice opportunities at slightly deeper levels).
Normal start time is 10 AM but this can be moved to 9 AM on request; this too
must be reserved in advance as the normal time of 10 AM is the default. Normally
there is no freshwater on the boat for cameras since they see few photographers
but again, on request, this need can be accommodated. The divemasters handle
cameras in an appropriate fashion and there should be no fear in this regard.
All of the dive sites are reached by fast boat in 20 minutes or less and all of the sites are relatively close to shore. Many of the dive sites such as New Guinea Reef are on the lee side of a point so they are exceptionally calm but none of the dive sites involved really rough water. The less protected dive sites have some surge at shallow depths. Water temperature was 82 F in December but that may be slightly warmer than usual at this time of year due to El Nino.
When you think of a dive location it is rare that you think of it in terms
of specific animals; however St. Vincent is an exception to that rule. When
I think of St. Vincent, I think of two animals: seahorses and frogfish. 
In the 18 dives I
saw and/or photographed about 20 different frogfish and a similar number of
seahorses. The most seahorses on a dive was six, the most frogfish on a dive
was four. Seahorses were found in the following colors: red, orange, yellow,
gray, black with white stripes, etc. Frogfish colors included: black, red, orange,
yellow, green. In addition to seahorses and frogfish, there were a multitude
of Spotted drums (both adult and juvenile), Flying Gurnard, Eels (spotted, viper,
chain, golden tailed, snake but no green), Blackbar Soldier Fish, Slender Filefish,
occasional French Angels (juvenile, intermediate, adult), Squirrelfish, Octopus,
crabs, shrimp, Bristle worms, etc. There were many diving highlights but some
included: mating cowfish, a viper moray that had eaten a cowfish whose profile
was easily identifiable within the eels stomach, pregnant Pederson Shrimp, shallow
black coral, etc. 
Favorite dive sites included: Orca Point, New Guinea Reef, Turtle Bay, Anchor Reef, Pinnacle, Emry's Wall, the Wall, and Steppes. Currents were occasional but mild even by Caribbean standards. There were no drift dives.
We stayed at Young Island which positions itself as an upscale luxury resort.
There are good things about Young Island and things which are not appropriate
to a resort costing $500 per night. Good things: rooms are spacious, well appointed,
kept meticulously serviced for fresh towels and supplies and have wonderful
views; meals are incredible both tasting delicious and providing gourmet island
fare; personnel are friendly, accommodating, and anxious to please; pool is
nice and convenient; office personnel are friendly and accommodating; Bianca
Williams, the general manager is highly guest oriented. Bad things: climbing
a large number of steep, uneven stairs carrying camera equipment and the
noise from across the channel from the nightclub on Saturday nights and special
occasions. This last negative is enough for me to choose a different
hotel on my return to St. Vincent. If you book your accommodations through
the dive shop, discounts and packages are available; next time, I will certainly
avail myself of this service. The dive shop does not make money on these bookings.
In December (1997) the weather was sunny for all but some short periods of rain, warm during the days, temperate at nights with continuous, moderately strong winds. Seas were relatively calm but some of the more unprotected dive sites had moderate waves and some had slight surge. Calmest weather in St. Vincent is in July/August/September but it is also the warmest and least crowded.
I must confess that I have a preference for live aboard boats and the diving in the Pacific almost always will beat the diving in the Caribbean hands down, but for convenience and excellent Caribbean diving featuring frogfish and seahorses, I strongly recommend diving in St. Vincent if you are considering the Caribbean. You could not get a more customer responsive dive operator than Bill Tewes and Dive St. Vincent.