Philipsburg, St. Maartin: One of the Northern Caribbean Leeward Islands, the southern half is Dutch, and the northern half is French. We have been here three times; 2005, 2009, and 2010. It remains as my most favorite island. In fact, I could see myself living here. There is a lot to do here, from snorkeling, scuba diving, fishing, laying on the beach - you name it. And my favorite; the St. Maarten 12 Metre Challenge. That was simply a blast; so much so that I am providing a link here to their website.
The race consists of crewing actual America's Cup craft, of the late '80s vintage. The sailboats have only been slightly modified; the boom has been raised so it doesn't knock passengers off-board, and the sails are not raised quite all the way (to slow them down a bit). Other than that, you are under real-life race conditions. This excursion does take some physical effort, as you will be manning the winches or grinding on one of the sails. There is a "professional" crew of 3 or 4, including the Captain, that help you in your tasks.
If you do not wish to participate in the physical deeds, you can become a "beer-babe", and pass out beer on the down-wind legs of the race. The race consists of several laps, and you race against one boat. The boats can come quite close to each other during the tacking operations in the race, and often you get the chance to jeer at the other boat you are racing against.
When we were there, the "Christmas Winds" were up, and we really got going pretty fast. We were on the Canadian boat "True North", and were racing against the US boat "Stars & Stripes". Unfortunately, we lost the race by just inches; but that's OK, we had a lot of fun anyway.
One word of caution, this excursion sells out, so if you really want to go on this excursion, book it early via the cruise line's website. The cruise ships dock in St. Maarten - the Dutch side on the south, and its not uncommon to find several ships in port. The French side on the north half of the island is known as St. Martin, and is only a short distance away.
Like many of the Caribbean islands, things are way laid-back in St. Maarten. Crossing the border between the Dutch and French side is basically as simple as driving by a marker by the side of the road.