On Saint John dollar drinks are available across the street from the National park office, next to the ice cream shop.
On St. Thomas, There are several drinking establishments in Red Hook, on the East End, including: Caribbean Saloon, Duffy's Love Shack, Fat Boy's, Molly Malone's, Island Time Pizza, and XO Bistro.
On St. Croix, Cruzan Rum is made at a distillery that you can tour. Be sure to do the tour and participate in the tasting after! Cruzan Rum is available just about everywhere, but there are certain flavors ie Clipper that are not sold in the USA, so take a bottle back with you. In the seaside town of Christiansted is the Brew Pub which makes several good beers. And, when at local places or events, always ask if there is a local drink. Be wary of the home recipes ie Mama Wanna - they are STRONG!