Karen & Cathy,
A brand new ship is always a great introduction to cruising!
Be sure to book "shore excursion" STT-R, "Champagne Catamaran Sailaway to St. John," from St. Thomas. This is one of the most enjoyable excursions that I have found anywhere. A sailing catamaran will meet you right at the cruise ship pier and set sail for a secluded beach on St. John with a reef nearby for snorkeling. Upon arrival, the crew anchors the catamaran and lowers a ladder at the bow into the water for easy access, and breaks out snorkel gear for those who wish to use it. The crew also will provide free snorkel lessons for those who wish to participate. While at anchor, they will serve a cold buffet lunch aboard the catamaran. After lunch, they take up the anchor and sail right back to the cruise ship pier, arriving around 3:15 -- right in time for tea aboard ship or, if you prefer, allowing plenty of time for a couple hours of shopping in Charlotte Amilie before the ship's departure at the end of the day. I have done this excursion three times, and I look forward to doing it again on my next visit to St. Thomas!