The following is a "cut and paste" from a previous thread I responded to on the same subject.
a warning about the Grand Cayman Island Tour. We took the one which was sponsored by Disney. It was very disappointing. So much so that practically our entire tour group complained to guest services. And the CM I spoke with at guest services had been on the tour earlier in the year and her opinion matched our own!
The tour guide could barely speak his own native language let alone english. He told us nothing about Grand Cayman except that he was sorry because on this day the rum factory was closed. It became his mantra. I asked him a few questions about the international banking which Grand Cayman is known for. Yes, he said, the island has many banks. They are open. The rum factory, he was sorry, but that day it was closed. On top of it all, I don't drink alcohol.
The Grand Cayman Island Tour also included a boatride to an off-shore semi-submarine which remains motionless in the water as you sit there in rather uncomfortable seating. I think most of the fish were laughing at us. The boat guide spoke english, so we could easily understand when he explained that the semi-sub's tape player recently broke so no information was currently available as to what we were seeing. Well, at least the windows on the semi-submarine were clean so we could clearly see what he couldn't explain.
Another forgetable thrill was visiting Hell while on the Grand Cayman Island Tour. Although vapidly "cute," it shouldn't be listed as a "major" sight to behold.
Our bus driver was a real piece of work. His driving was as adept as his command of the english language. Oh, by the way, he couldn't speak any english. We travelled on what appeared to be a major thoroughfare and then on (obviously) lesser travelled roads. Poverty appeared to be rampant. Paving appeared to be optional. But rest assured the friggin rum factory, unfortunately, was that day closed.
When we finally arrived back where we started, both literally and figuratively, I paused to listen to our surroundings. No, no fat lady was singing.
After such an enlightening tour, I was almost ready to give up on any hope of learning about/enjoying Grand Cayman. Fortunately, my son and I didn't return to the Magic immediately after the "tour," even though the rum factory was that day closed. We had made arrangements months earlier to go horseback riding along an isolated beach with Nikki's Horseback Tours. Not only was the ride absolutely fantastic, but when Nikki learned of our disappointing island tour she drove us around some lovely local areas and provided insight into Grand Cayman's history. All this was at no additional charge and on her "own" time - my wording, not Nikki's.
So give some thought to the other options available to you in place of a Disney-sponsored Grand Cayman Island Tour. If you don't care for horseback riding, then perhaps you might wish to try Captain Marvin's. They have gotten such rave reviews that DS and I will definitely try them on our next cruise - along with yet another ride with Nikki.