If visiting Anguilla for the day, and you want to swim, relax and maybe snorkel, I would settle on one maybe two beaches at the most. Shoal Bay East is ranked one of the most beautiful, Meads Bay is also very nice. Each have some little beach bars for lunch and relaxing. Taxi from the ferry could give you a quick tour on the way to one of these places. Junior Fleming has a glass bottom boat on SBE and could probably give some kind of water tour. We went to Little Bay with him which had great snorkeling. Sunday is music day on Anguilla. Anguilla is beautiful! Enjoy your trip!