We had such a wonderful time in St. Maarten. We had a full day in port that started with a walk to the beach in Philipsburg. Its under a mile from the ship to the beach (walk out of the port gate, then turn right, follow that main road past the shipyard and you will start to see stores after about 10 minutes. Through those stores there is a walkway that puts you right on the beach). If you get off the ship early, the beach is practically empty. There are plenty of folks trying to get you to rent chairs and umbrellas. We got 4 lounges with 2 umbrellas for $15 for the day, which included WiFi access. Note that the beach in Philipsburg is small, and the water taxis run right up to the beach marker, so you don't want to go too deep into the water They have no respect for swimmers other than to gesture to them to get out of the way. We also had guys trying to get Jet Ski rental business run their skis right into areas where people were swimming. A little dangerous in my opinion. There is no lack of food or drink or shopping on this little stretch of beach, and prices are reasonable (especially for drinks as compared to what you are paying on the ship!)
Our great adventure, though, was renting scooters to go all around the island. My wife and I are experienced motorcycle riders, so we felt fairly confident in taking our daughters (ages 7 and 8) as passengers on scooters. Now, if you are not used to being in traffic on two wheels, do NOT ever do this. The islanders are tolerant of scooters and other two-wheeled conveyances, but there was the occasional arse that would cut you off or not respect your lane space. Just ride like everyone on the road is trying to kill you and you will be fine. Note that intersections are for the most part roundabouts. If you are not used to negotiating roundabouts, again, do not get on a scooter.
We did ride from Philipsburg all the way around the island, to the french side and to the town of Marigot. We stopped at the Marigot Visitor Information Center on the southern end of the market. The folks there were very helpful and pointed us to the entrance to an old fortification. It provided a wonderful view of the market and the bay. After a brief stop in the open market, we continued around the island through some very rustic countryside and some wonderful views, and came around to Orient Beach. The bay it sits in was very pretty, but we did not stop at the beach since we had kids with us and had heard that the beach was clothing-optional. Not our thing especially as a family! We continued our scooter tour, and got back around to the Dutch side and ran right in front of the cruise port. We dropped off the girls with a friend, and took the scooters back to to the rental shop. We had the scooters for about 5 hours, and the cost was $50 per scooter (plus the about 6 liters of fuel). Definitely would recommend it to anyone that is used to riding motorized cycles and is not afraid to get lost a couple of times!