I was not able to figure out why the change. As soon as we pulled out of the Miami port, flyers were passed around announcing it. I went straight to customer services to inquire as that was one of the main reasons that I chose that particular voyage. I was told as were other customers there that the captain wanted something mechanical checked out. When I questioned this since St. Martin was their last port before returning to Miami, I was told that the captain has the right to change ports at any time during sailing (the little fine print on any sailings). I spoke to several customers during the 12 days sailing and they were given the same dialogue. One couple was doing a back-to-back and they found out on the last at sea day on our 12 day voyage that St. Martin was again changed to Tortola. So, I definitely felt that there was something fishy about this, but did not get a straight answer. The only thing that I could see was that it was during November and December of last year is that St Martin had as many as 6 or more ships in port on some days. This included the day that we were to be there.