It's hot and humid. Think about it: You're in the BVI because you live where it's cold. And in the humid environment aboard, it might be a good idea to make your short (and expensive) vacation as pleasant as possible. My vote is to get the A/C. You can always turn it off. We did 10 days aboard a 474 PC and ran the A/C most nights. Our fuel bill was just over $300 for generator and engines; a small fraction of the thousands the trip cost us.

Get the A/C!