I know there are FOs based in SJU, however, I'm not sure about MAZ. All FOs bid with their relative seniority on a system bid, so if the company decides to keep FOs down there you certainly have a shot if your seniority allows for it.

My suggestion is if you want to fly in the Caribbean go as a captain, its pretty junior year round so you could hold it, plus you'll have a little more disposable income to enjoy what the region has to offer on your days off.