Just in case anyone else is trying to find an answer, here is one that I got from a skydive specific forum:
I went to the island about 4-5 years ago for a family vacation. The guy that was running the "DZ" actually had it listed as a Canadian CSPA affiliated DZ. It was listed there for many years in the Canadian Canpara magazine.
I sent dozens of emails to the two accounts I could find asking for information about skydiving before I left but never, ever received a reply. I made other plans for activities while there and didn't plan on skydiving at all because of that.
I happen to be near the airport one day so I popped in during the middle of the afternoon to check it out. The only guy there was the janitor sweeping the floor. I asked him whats up with the skydiving listing and he told me that the guy that does it is basically a bum. He lives in an apartment down the road and he owns a tandem rig. When ever he is stressed for money he rents the local cargo plane and takes a few tandems up for cash when the cruise ship people are wandering around downtown.
When I got back from the trip I tuned in CSPA to what their DZ was up to and by the next issue, the listing was removed. Like I said, that was about 5 years ago and someone new might have taken over the business but unless you can contact these guys BEFORE you leave and get a response, I would err on the side of caution and think that nothing has changed.
Remember that they are their own country with no CSPA affiliation. Are they a current rated Tandem Master? Has the tandem rig ever, ever been back to the manufacturer for its re-certification? Check the rules because St. Maartin is it's own island and has its own skydiving rules (if they even exist).
Good luck. Man I love the internet, it is so awesome. almost 10 years ago