So we did the TT21 on our April 17th sailing. We grouped up in Fathoms around 12:30 I think. We walked out to the dock and loaded on the catamaran named "No Fear". The engine ran the whole time, they did unfurl the large sail as well once out of the bay. We sailed to Norman Island to a little cove on the Western side of the island. Then for about an hour, maybe an hour and half we snorkeled in some calm and clear waters. It wasn't a huge reef system, but there were a lot of fish, we saw a turtle, and we saw a ray - I think it was a manta ray.
We then re-boarded the ship and sailed to "Pirates Bight" just around the corner of the island. There was a bar, a couple of shops, a few chairs, and a number of private yachts in the harbor. After about an hour at the beach we boarded and sailed back to Tortola.
We got a couple of punch drinks while on the catamaran, no lunch or snack.
We loved it, would do it again for the price. The kids had a blast, the snorkeling was fine. Sitting on the netting on the bow of the catamaran was great.