All of our excursions were booked through the celebrity website prior to the cruise. We snorkeled in every port. Our favorite excursion was the snorkeling with "Bones" in St. Thomas. You get off the ship and walk to the end of the pier and board their pirate ship schooner to sail/motor to turtle cove and another place. The crew was excellent, the beach lunch was great and the green sea turtles were amazing! We would definitely do that excursion again! This was a 6.5 hour trip so there was no time to do anything else in port.
All of our excursions were booked through the celebrity website prior to the cruise. We snorkeled in every port. The only bad experience, if you can call it bad, was the snorkel excursion in St. Lucia. The catamaran was very nice but the crew did not seem very prepared for gearing up snorkelers with equipment. they had no organization to the fins and had no cleaning fluid filled bucket for the masks and snorkels. I was convinced I would get some nasty germ from using the equipment but luckily did not. My husband only snorkeled a short time because the fins he had to use were too small. The current was too strong in the area to go it with out fins.
We did the rain forest tour prior to heading home on a 4:20 pm flight. If you have the time i would highly recommend this as opposed to sitting in the airport all say. We had a wonderful tour guide "Charlie" who has been doing this for 17 years. He was great! This tour also drops you and all of your luggage off at the airport.