Here is Captain Morgan's website:
We joined them on the day sail in June '05. They and Random Wind meet their guests at the same location near Simpson Bay and travel the same route. Sail from Simpson Bay around to Creole Rock by Grand Case on the French side, stop for snorkeling awhile at Creole Rock, then about a 30 minute stop at the secluded Happy Bay beach. For return trip, you go back the way youu came. (not an full sail around the island as you would not enjoy coming around the island onto the rougher Atlantic side)
You will meet them early morning and return about 5pm. Oddly enough, I most fretted about what kind of shoes to wear for sailing as I had not been on a sailboat before --- when they pick you up, they place everyone's shoes in a plastic tub and return them to you back at the dock --- no shoes worn onboard. Light snacks, then lunch, drinks of varying variety all provided.
We did have a beautiful day for sailing -- light breeze and slightly overcast. There is an area that is shaded if the sun gets to be too much. No more than 16 - 18 people which did not seem like too many on a ship of this size.
It was a nice way to spend a day during our seven day stay on St Martin (Grand Case).
The Random Wind should be similar from all I have heard. It is the more recognized name as they were "there first". Their site: http://www.randomwind.com/
Enjoy your day!