Our table mates on RCI last November did an excursion with the ship on Jeeps. Each party drove their own Jeep and all went out together as a group. If that's not offered on your itinerary, I'm sure you can get that info in port when you dock and do it on your own. They had a lot of fun, but came back, hot, dirty and exhausted.
Thanks cruisecrazy2. I really don't want to take an excussion since we have been to Aruba, but long ago and had a blast with just the two of us. (our honeymoon) I only wanted to know of a place a head of time to rent a jeep that is close to the ship dock, so when we get there everything is set. Yes, excussions are great and we plan on doing one in every port.......but Aruba.