One of the most popular travel routes to the Virgin Islands is via St Thomas, USVI. If you are based in North America, you can fly into St Thomas (STT Airport) and take a ferry over to Tortola.
There are three different ferry operators who operate services to-from Tortola and St Thomas. They take turns on which days they operate. This means you may not take the same service coming into to Tortola as you would going back to St Thomas. You may only book ONE WAY tickets in each direction. Please make sure to check the schedule to check which ferry operating is providing service before you book via their website.