You didn't mention parasailing, you may find that available in most of the ports you listed. They also have a fun jet ski excursion in Coco Cay.. Actually the snorkeling is pretty good there too. In St. Maarten they offer the AMerica's Cup Regatta, which is also a lot of fun and work if you wish.
I'd suggest going through the list of excursions on their web-site and it gives you an idea of what is available at the ports.