I try to locate an outdoor sand volleyball game on every island that we visit. This is what I've found.

Georgetown Bahamas has the best courts, equipment and games so far. There are beginner 9x9 games and slightly more advanced 4x4 games. And, occasionally there are advanced level games (strict rules) for the better players if you are good enough to be invited. There is almost always enough players to play. They have rules which keep kids playing with kids (most of the time). It is all fairly well organized by the regatta committee, and avoiding injury is a high priority.

Boca Chica Dominican Republic has a couple unorganized courts on the beach about 1/2 mile east of Marina Zar Par. Bring your own ball because they won't have one. In the early afternoon, you'll have no problem finding people to play, but they will be mostly young people and kids. But, most of the kids have reasonable skills. Later in the afternoon the better adult players will arrive, and the kids will respectfully relinquish the court (this is unlike anything I've seen in other places). The games are vigorous and enthusiastic. These guys play with gusto. I loved it!!!

Sapphire Bay on St Thomas has a nice court at the Sapphire Bay resort. But, bring your own players because you'll have a difficult time finding players.

In Gorda Sound of the British Virgin Islands, you find a court near the Sand Bar and Restaurant. You can obtain a ball from the bar by leaving a deposit. When the cruise ships arrive, you'll have little problem finding enough players, but the quality of the play is hit and miss. Too often you'll find a kid who can't play but insists on standing in the middle of the court as an obstruction. And, since charter boat and cruise boat parents feel that have paid a large fee to have fun, they feel completely justified in allowing their kid disrupt your game. So, a considerable amount of patience is required to play.

I found no outdoor sand volleyball in the Bahamas Islands south of Georgetown, Puerto Rico, Spanish Virgin Islands or St John.