Hi Candice R, if you'll look a little further down on our main page, you'll see the Caribbean Port Chat section. You can use your "find" feature in the upper left hand corner, type in your ports, and it will pull up all the posts made about them.
Coco Cay is their private island, it's a great beach day, bar-b-que and snorkeling, plus water toys. I agree with Dave about the dolphins, although Tortola is a beautiful island, you're spending most of your time traveling. That could be enjoyable too. I recommend going to St. John and then to Trunk Bay. It's one of the top 10 beaches in the world. We did a great snorkel excursion in St. Maarten to the Tikihut. The web site was something like snorkelstmaarten can't remember. We did it through the ship, but I don't remember if the contracted with RCI. We were on Celebrity, so it's possible RCI offers the same excursion.
Anyway, take a stroll through the Caribbean section, there are tons of posts there. Have a wonderful cruise!