Definitely a place to shop, eat, or book a ship's excursion. Lots of stores selling lots of things - local specialties to look for include cashew wine and Marie Sharp's chili sauces. Due to the need to tender in and out, I would book ship's excursions, just to be on the safe side.
Great port - lots to do. We took a ship's excursion on another cruise, unfortunately this time there were so many ships in port that we had to tender, so we didn't even get off the ship. Be aware that this is a popular port, and that having to tender is a possibility when planning your day.