We have ATT and can typically get on their direct network from Norman, West End, and JVD as well as in the USVI. ATT has a plan where for $10 a day you get data usage and unlimited texts (on the local network) with the minutes taken from your subscribed plan at no extra cost. Phone calls can be pricey though if you are going through the local carrier (Flow, CCT, Digicell). Be sure to sign up for this before you go as if not, the data charges can be quite a surprise when you get back and see your bill.

I use this frequently for international (and island) travel with no issues.