Welcome aboard, Inco!
My favorite Port Adventures in Grand Cayman are any of those that include the Turtle Farm! With so much to explore there and even the chance to get in the water with the baby sea turtles, this experience is not to be missed. You'll see that either the
Boatswain's Adventure Marine Park adventure takes place entirely at the Turtle Farm, while other adventures include the farm as one of their stops. If you eat there, don't miss the conch burger. Delicious!
In Cozumel, I really enjoyed the
Ruins and Beach tour earlier this year. I like that we got a bit of native history at the ruins, then got to cool off and relax at the Playa Mia Beach Resort afterwards. If you'd prefer to just head straight to the beach, the Cozumel Beach Break takes your family to the Playa Mia Beach Resort and also includes the waterpark area.
Costa Maya offers quite a few great adventures as well, Inco. Check out the ruins tours there if you don't opt for the ruins in Cozumel, or perhaps the Jungle Beach Break would be a great way to spend the day!
If you don't want to do adventures in every port, I'd save Castaway Cay as the one on which to skip the Port Adventure. There is so much to explore, many activities including character dance parties, crab races and more, so you can easily be busy the whole time, or simply enjoy relaxing on the beach. However, if you would like a formal Port Adventure, pre-book the Castaway Ray's Stingray Adventure, which is a really neat opportunity to interact with these amazing creatures in a beautiful setting.
Have fun planning, Inco!