Probably one of the best ship-purchased shore tours we have ever done. The pace and timing were completely spot on and the two girls who were our instructors were fantastic. They were informative, fun and enthusiastic. This was one of our highlights on shore.
We have only found Cave Tubing to be of interest to us here and we've done it on our last three cruises. We always book a private tour (we generally travel with at least 10 friends/family) and this time we used Belizean Adventures and they were great, especially with two issues with our group. We had my five year-old son with us and he's not a great swimmer (this was his first cave tubing) and my aunt is terrified of water (she doesn't swim at all). The guide was great and the experience far exceeded our expectations.
Carnival docks at the brand new Mahogany Bay port. I love that you can walk to a little beach and the entire port area is pristine. We generally do a private shore tour with Pirates of the Caribbean (extreme zip lining).
I'm not thrilled with swimming with stingrays, so we just took a taxi to 7-Mile Beach, which was perfect for my son to play in the sand and swim a bit. Taxis were $4 per person, beach chairs $10 per chair and umbrellas $10 per umbrella. This was about half the cost of the cruise line's shore tour.