Located near the center of the island on the north coast, one of the best-known beaches on Tortola is Cane Garden Bay, which is as much a beachside community as it is a beach. Lined with restaurants, apartments, hotels, and watersports vendors, Cane Garden Bay is by far the most populated beach on Tortola as well.
Cane Garden Bay is a well-known surf spot. In the winter, the waves usually run six to eight feet in height, but with the break far out in the middle of the bay, it's not for amateurs.
Being the closest beach to Road Town (only about 15 minutes' drive), it is also popular with cruise ship visitors who want to spend a day on the sand, and so in winter, this very wide, very long beach can be packed with people.
CGB is also popular with the boating crowd, as it provides the best and safest mooring on Tortola's north coast. While the north coast is littered with coves and bays, Cane Garden Bay is one of the only ones deep enough to accommodate sailboats.
While I personally don't like to visit Cane Garden Bay on super-busy cruise ship days, you really can't beat it for a place to spend the day at the beach. Beachside bars and restaurants like Callwood's, Myett's, Rhymer's and Quito's provide good views, good food, and good relaxation.