Like any good sailing destination, Tortola has plenty of excellent watering holes. Many offer entertainment; check the weekly Limin' Times for schedules. Jost Van Dyke has a large number of informal bars and restaurants, which have helped earn Jost its reputation as the "party island" of the BVI.
The local beverage is called "painkiller," an innocent-tasting mixture of fruit juices and rums. It goes down smoothly but packs quite a punch, so give yourself a moment before you order another.