Not likely. I tryed to book the sub the minute shore excursions opened in advance with Disney, 60 days before our 12-27-03 cruise, and it was already sold out. To book it yourself you'd have to do it once you got to St. Thomas and I suspect all slots are presold by then. Remember, normally there are 4 other ships in port with you, so you have 10,000 potential customers competing for about 240 slots each day. If you went on another ship, that didn't arrive on Wednesday, you might stand a chance. Everyone in St. Thomas told us Wednesday was the big day because there are more ships in on Wednesday. The sub is worth it though. Wife and I did it on a cruise on the Soverign Of The Seas in 1988.