We did the Rum Point beach excursion and loved it! You take a bus trip through Grand Cayman and come to a dock, and then take a ferry to the beach. The whole trip takes about an hour and 15 minutes. When you get to the beach, you feel like it is a private beach. There are condos and hotels there, but it was not at all crowded the day we went. The water is crystal clear and warm. There are hammocks and beach chairs to hang out in. There is a bar, and you get a ticket for a free lunch, which was really good.
While we were there, we had a rain shower, but it passed quickly and made for some stunning photo ops. At about 2 or so, you take the ferry back and then the bus.
The ride over was a bit long, but this was an excursion we would definitely do again!
This is the link for the Grand Cayman part of our cruise trip report: Steve and Sue do a Magical Cruise:***Updated 7/20 - Day 8...a new adventure begins....***