We did this excursion about 4 years ago and I think we were on the Sea Princess at the time. It was a blast! We had one stop for snorkeling and saw some great things. Then it was on to Nevis. The one thing you should know is when we did this trip, the catamaran could not dock at the beach. They got pretty close, but you had to jump in the water and swim the rest of the way. If I remember correctly, the beach dropped off pretty quickly too. Wear some water shoes too. I would do it again in a heartbeat!
We are doing the Golden March 11 and will be doing the ATV tour this time out. I am keeping my fingers crossed that this will be just as much fun!