Can't personally recommend them but here are a few you can look into.

Sadie Sea Charters. Actually this recommendation came with great reviews from the condo owner we are renting from. http://www.sadiesea.com/

Cruz Bay Watersports at the Westin http://www.divestjohn.com/snorkel.html

Motor Yacht Cinnamon Bay
http://www.motoryachtcinnamonbay.com/outer-cay-snorkel.html

Calypso http://calypsovi.com/private.html

Most sail boats take out 6 people but you can ask them to sail with one of their friends in two boats as another option.

Calypso does a good job but you will probably be with other people. If you would like to go by yourself "outlaw" (www.sailoutlaw.com) can accommodate up to 12 people and they do an excellent job but they are a monohull.

You may want to try True Love - they are out of STT, but I think will do STJ pick ups.

http://www.sailtruelove.com/home.html here is the link to their site. The phone number is there.

Absouletly beautiful boat with a lot of history and is the ultimate sailing experience.

There is a beautiful classic malabar 7 just waiting to be chatered. 340-513-0655..