Stay away from the airport beach bar at Maho on heavy cruise ship days. One or two cruise ships of the smaller variety may be fine, but when a couple of the big ones are in it becomes not worth going. Others will have more detailed advice.
The zip line at rainforest adventures is worth doing. Check them out. They may be closed if no cruise ships are in. The view from the top is the best you will get anywhere on the island.
.
