Just returned from a 4 night Carnival Cruise on the Fascination. We do not have any negatives about the cruise or the boat and would not hesitate to book again with Carnival.
The Fascination port of calls were Key West 8-1:30 pm and Calica Noon-7:30 pm, other than wishing for a little more time in each location did not have any problems. Key West we did on our own but the ship does offer excursions. One good thing that is great about Key West is the ship is docked right in the middle of everything.
In Calica we booked the Caverns and underground snorkel excursion. We all liked this tour very much and it exceeded our expectations. The caverns are beautiful and the water cold but was well worth the price of admission. The equipment is provided for you, the snorkel was new and in a wrap that you could take with you and the masks were US Divers and in good shape. A light is provided to you and it is expressed that the equipment is your reasonability so don't let it get away from you. The one thing you might want to have is some water shoes because it can be uncomfortable in some places to walk. There are vendors on sight so you have the opportunity to shop if you want. Also if you ask the bus driver and tour guide after the tour they will drop you off in Playa Del Carmen on the return trip and you can shop and get a taxi back to the boat.