We did the catamaran sail and snorkel and had a great time. At the time, ds-12 and niece -12 really enjoyed it. Nephew was 7 and loved the ride but didn't really care to snorkel. I think he was just being difficult though. Sorry nephew!!!
Timing for this was great. We were back around 1 for lunch, got cleaned up, went into Nassau for a few hours and back for spa appointment at 5.
If you have any specific questions, let me know.