excursions with kids-S. Caribbean

[crewmom24]

I haven't booked any excursions yet for our Crown Princess cruise leaving March 15th. We are taking our 20 mo, almost 4yo, 13 yo and 15 yo. We depart from Puerto Rico then go to St. Thomas, St. Kitts, Grenada, Bonaire and Aruba. My 15 yo ds would like to try scuba and since it has been 10 years since my last dive, I would just do a discover dive with him. Maybe the rest would stay on the ship or go to the beach while we did that. I would love some suggestions for these ports. I just don't know what we will be able to do with the 20 mo along. We could take turns staying on-board with her or sitting on the beach while the rest went on an excursion. What have you all done at that age.

Debbie