Seeing as you have not had any answers, I will tell you about our trip on Majesty of the seas. It was our very first cruise many years ago. About 1995. The riuns we visited were on the mainland. Tulum. Absolutely fascinating. It was a half day trip, we were told not to eat anything on the mainland. Royal Caribbean even packed us our lunch. Well worth seeing them. Not sure about the 8 hour one though. Grand Cayman, Turtle farm, Hell and the stingrays great also. Dunns river falls, Jamaica. Barbados, Jolly Roger, hilarious. All the other Islands nothing spectacular. Apart from St.Johns. Hired ajeep with some american friends and went to Magans bay. Truly wonderful. One of the top ten beaches in the world then. Have a wonderful cruise.
We visited the Mayan ruins on Cozumel itself and quite frankly it was not worth the effort!!Very little to see and pretty pricey(this was with Celebrity but the principle is the same!!) On Grand Cayman, try the Submarine trip; the sub. is small ; about 30 passengers and you see an amazing amount of fish, turtles etc, not to mention the coral wall itself. If you call at Key West, the tram ride is fun and it's a great place to wander with v. pleasant bars for a little liquid refreshment along the way .. Cynthia .