St. Maarten is one of our favorite Caribbean ports. We always rent a car (we found Arthur's Car Rental just outside the cruise terminal years ago, and they are always friendly and less expensive than the majors) and set out on our own. There are many secluded beaches on the French side to visit, and we always end up at the Sunset Grill by the airport runway to have lunch and a few beverages, and watch the planes come in right over your head. Great fun. Just allow plenty of time to get back to the ship since traffic can be slow if there are several ships in port.