Ahoy, Frank!
The Western Caribbean is my favorite Disney Cruise Line itinerary! I absolutely love George Town, Grand Cayman. Since you are traveling with a little one, I have looked into some of the best family-friendly Port Adventures for you.
Boatswain's Adventure Marine Park looks like a fantastic day spent on Grand Cayman. This includes a tour at the Cayman Islands Turtle Farm, which my children loved!
In Cozumel, you might try the
Mayan Cacao Company and Island Tour. I do love any tour that I will get to try chocolate! You also should see some breathtaking views while touring.
If the Fantasy stops in Falmouth, Jamaica, on your cruise, I think you could try the
Good Hope Estate and Carriage Ride. While I have not ever done this, it looks like fun and has a kid's play area where your son could get some energy out.
On Disney's Private Island, Castaway Cay, you should simply plan to find yourselves a nice umbrella with some lounge chairs and a view of the most beautiful beach ever. Grab some sand toys for your son and plan to spend the day sipping frozen adult beverages, building sand castles (or sand piles in my case), and splashing in the clear water with your husband and son. It truly is an island paradise.
I hope this helps with your cruise planning. Please visit us again with more questions before you set sail on the gorgeous Disney Fantasy NEXT MONTH! (Can you believe I just said that?)
Happy Cruising, Tracy V.