Yes, FDF is central to the rainforest in the middle of the island, the west coast to visit St. Pierre & Mont Pelee, but you can also reach the south coast beaches and Josephine's birthplace. If you want some beachfront living, stay at one of those places for a couple nights.

Actually, if you can get out of FDF to explore the rest of the island, I'd do it. The traffic can be terrible, and you could get around a lot more easily if you based yourself at a quiet small inn or hotel in the countryside. Many of these have kitchens. Of course, if it's a lot cheaper or more convenient to keep the apartment, then do that. But I think you'll find it more comfortable and pleasant to get out of Fort de France. Despite all the improvements there (and I've heard they are considerable), it's not a place I'd really want to spend any amount of time if I didn't have to.

Thank you both for your insights. I'm actually renting an apartment with a (sliver of an) ocean view in Trois-Ilets and then taking a ferry to FdF. I've heard that public transportation is unreliable and traffic is terrible, so I'm thinking of renting a scooter~ has anyone done that?

I don't think a scooter is a good idea in Martinique, which has a lot of hills and variable weather, unless you're an experienced rider. I only have experience in Mykonos and Santorini, but friends rented scooters there and had accidents, one of which sent my friend to the hospital, though thankfully not for a serious injury. I'd stick with a car, despite the costs.

Thanks for your suggestions, Doug. I really want to see as much of the island as possible that's consistent with doing the work I need to do under the terms of my grant. Luckily, a sccoter is my main mode of commuting in downtown Colorado Springs~ if I can deal with the SUVs and libertarian driving of my Colorado fellow citizens, I could probably manage Martinique~!

I would also suggest that you rent a car as there are quite a lot of mountains. Plus you might want to avoid getting either sunburnt or completely washed out (it rains in the rainforest) and it is a tropical climate so you should expect some pretty heavy downpours. Alternatively you can book trips in a 4x4 to the north or south (see website www.lebonplanenmartinique.com).
It is only about an hours drive from Trois Ilets to Saint Pierre by car, so you could keep the apartment as a base. I would recommend you explore the wild beaches on the south and eastern parts of Martinique. A catamaran trip is a very pleasant day out. Good beach and restaurant in Grande Anse d'Arlets at Ti'Sable.

Thanks, Doug. One more question: it seems that I don't need a visa, just a valid passport, as I am a US citizen, but I haven't been able to confirm this from an authoritative source on the web. Hoping I don't need a visa, as I leave on Sunday!

Unless you are working for a salary, you don't need a visa to visit Martinique. You definitely do not need a visa to travel there for tourism. Academic research (non-paid since you would, presumably, be an employee elsewhere) shouldn't present any problems, but it's a little late if there are issues you haven't considered. Just write "tourism" on your landing form.