ScurvyDog, you asked for info on the Fan-Ta-Sea shore excursion.
A short walk from the pier in St. Kitts, you board the beautiful, sleek, new catamaran called "Irie Lime". Why lime, I don't know because it is very yellow!
The crew are 4 young, fun guys who take good care of you, especially at the bar. They play some mellow Bob Marley on the cruise outbound, while you enjoy the scenery of ships in port, and the beautiful island of St. Kitts.
Soon, you arrive at the snorkel area, and everybody gets their equipment and climbs down the ladder off the back of the boat. If you are in any way mobility impaired, this might be very difficult.
After the snorkeling, the catmaran sails again, to the island of Nevis, where you all go ashore and are treated to an excellent all-you-can-eat ribs, chicken and salad lunch on the beach.
After lunch, you can spend some time relaxing on the beach, which has no chairs or other facilities, just natural beauty.
The real party begins on the sail back on Irie Lime, when the music is pulsing and the rum punch is flowing, and everyone is dancing. It was quite the party, but I sat up front watching the horizon, so I wouldn't get sea-sick (it worked!) Nice view too!
So yes, I would recommend this excursion, it was a good time!