Took a private catamaran trip with our 5 adults. Great way to relax and get away from the crowds. You actually get to experience sealife without alot of people around you. Better than getting on a CATTLEmaran. Snorkeled around St. Johns and spent 7 hours sailing which was great.
Took a shuttle to Carlisle Bay...city beach near the cruise terminal
Beautiful beach and swam with sea turtles. You will be pestered by locals selling their crafts on the beach...alot. Also, there are a group of guys that will approach you to pay for a short boat ride out to see a shallow shipwreck and see seaturtles. They start by telling you it is $35 each and keep coming back and lowering their prices. They take you to the left side of Carlisle Beach near the bouys for 1 hour. If you can swim fairly well, bring your own gear and you are much better off. Once we got out there with this guy, he didn't even offer fins. When we were done snorkeling by the shipwrecks,he was on the phone with his buddy on the beach and made us go ashore to pick up more people before we could go back out to see the turtles....a waste of time. He then overloaded the boat and we were all uncomfortable....people standing, not even seats. Its a real racket. Bring your own gear....much more sanitary as well.
Take a Land and Sea tour on this island. Went with Herod's tours.
Even had a creole buffet lunch at his mom's house and sat on her veranda overlooking the Piton Mountains. Herods does a good job and you will really get a flavor for the island which is lush.