Both Fun
I've done both areas multiple times and had a great time. From St. Martin, with enough time and permission from the charter company, you can sail to Anguilla, St. Barts, Saba, and back to St. Martin. With the exception of Saba, all of the other main islands in this group are heavily touristed. In St. Barts, most boats med moor to the town dock (back in and tie the stern to a concrete pier). It's usually tight and like parking your car in a parking lot. You can reach from one boat to the next. Saba is one of my favorite islands in all of the Caribbean. Very few boats go there. Charter companies are not eager to allow travel there, and your crew will have to demonstrate via past experience a good deal of sailing skill. But the people of Saba welcome sailors with open arms. As you come into the small protected harbor, word of your approach will circulate through the island, and cars will come down the single, impossibly steep road to meet you. The harbormaster will come out to greet you. If you express an interest in buying lobsters, he will summon the lobstermaster, who will pull a huge cage out of the water, allowing you to pick your choice of monster lobsters. If you like to scuba dive, Saba has some of the best diving in the Caribbean. There is a dive shop that will take you out, or you can buy a book on the Saba underwater marine preserve that will guide you to all of the best spots. The top of Saba is a tropical rainforest that's a great hike. The only down side to Saba is the lack of a bulletproof protected anchorage. There are places to tuck in, and some of them have sturdy mooring balls that will guarantee that you won't move overnight, but they all can be rolly. The adventurous on board won't want to miss this place, those more interested in genteel sailing will be more than willing to skip it. Grenada is my other favorite island in the Caribbean. The land area is extremely diverse, allowing for lots of exploring opportunities. There are quite a few excellent restaurants. There are some lovely beaches. There are lots of excellent anchorages. Many of them are peppered with long-term cruisers, so if you want to talk with anyone about their experiences, if you're interested in doing this someday, they're all over the place. The people are great. And for some reason, Grenada is not heavily touristed. You can also charter one way from St. Lucia to Grenada, hitting St. Vincent, Mayreau, etc along the way.