Although the Virgin Islands [1] are surrounded by sea, most travelers will get to them by air. With the exception of cruise ships and a twice-monthly passenger ferry from Puerto Rico [2], no passenger ships sail regularly to the islands. Mariners with their own yachts, plus time and sailing experience, can include the Virgin Islands on a tour of the Caribbean.
Links:
[1] http://www.moon.com/destinations/virgin-islands/discover-the-virgin-islands
[2] http://www.moon.com/destinations/puerto-rico