Eastern Caribbean with an infant

[MrsZee]

We are trying to have another baby and at the same time we are looking to book the Carnival Dream sometime next October. (hopefully we will be pregnant soon and by next October, the baby will be old enough to travel) So, by then we will have a 3 year old and an infant (6-8 months). The itinerary we are looking at goes to Nassau, St. Thomas and St. Marteen.

 

I know in Nassau we want to go to the Atlantis aquarium and then I guess hang out at a restaurant on the beach for the rest of the day. But, I am clueless when it comes to the other two ports. I know there are always tours or beach days available... but have any of you taken your families to something in St. Thomas or St. Marteen that is must see, can't miss? I am finally venturing away from Cozumel and am totally overwhelmed to whats out there.