This is what the Carnival website says we will see
On this excursion you will:
Visit famous sights such as the Conch Shell House, the Governor’s Residence, the Old Cayman Homestead and the Turtle Farm.
Have the opportunity to view a town named Hell, named after a famous black jagged rock formation, which some imagine hell must look like.
Visit the world-renowned Tortuga rum factory to sample some of the finest rum cakes in the world.
In my opinion the best highlight of Grand Cayman is a trip to Stingray City for a swim with the rays.
Explorer of the Seas October 2013
Caribbean Princess July 2006, May 2010 & November 2012
Monarch of the Seas November 2008
Crown Princess November 2007
Celebrity Zenith November 2005
Enchantment of the Seas August 2004
Candy, Hell is an overated tourist trap, its a tiny post office in a rock formation that is jam-packed with tourists who want to send a postcard postmarked from Hell. The rum factory is nothing special. The turtle farm is a fun place to stop-you need a couple of hours here to see everything, sounds like you won't have much time to enjoy the stops fully.
I agree with Doug about doing a Sting Ray tour. Its amazing, you don't have to know how to swim,(make sure you go to Sting Ray City Sandbar) you stand in the water and the rays swim all around you, they are beautiful creatures.