I always have a 3 month supply and have never been asked anything about meds. I only have a few and half are OTC. I would not think it would be a problem from what I have seen and I pass in and out of
customs several times each trip.
You have indicated you will be working in BVI for 6 months... do you have your Work
Permit in place? You really need it prior to arrival, otherwise your stay is limited to 30 days. Most of us have no problem with this as we simply go to USVI for a few days/ weeks and return as often as necessary.
If you have an employer already signed up, they should be able to facilitate your Work
permit process. Generally it is somewhat difficult to get permits in such jobs as
Charter Capt as the local supply is sufficient. Not really sure about instruction but certified would probably fit in.