In Aruba you have plenty of time to hire a cab and get a private tour of the island. Be sure to see the Natural Bridge. Prices are reasonable, the last time we paid about $25 for the 2 of us.(We even had the driver stop by Ace Hardware for the much needed duct tape for suitcase repair). We like Senor Frogs across from the Seaport Mall for a late afternoon snack. (walking distance back to the pier) and then shopping or gambling at Seaport Mall.
Curacao-be sure to see the island!! This is our favorite island. Again, plenty of time for an island tour, either private or with the ship. We found the best prices on this island. Shopping is no problem here. Bring U S coins if shopping, the local stores do not have an abundance of them, especially the quarters. Hope you enjoy.
I did the cruise to Aruba and Curacao this past November on Grandeur. If you can spend about $75 a piece, the Atlantis submarine ride in Aruba was great, and in Curacao we took a cab to the Aquarium, I think it was about $10 each to get in, and $4 each for the cab.
The aquarium was fantastic, and one of the guides even took us on a "behind the scenes" tour of the aquarium.