U.S. Virgin Islands Diving

St. Thomas, St. Croix and St. John are sister islands, but each has its own special character. St. Thomas, the quintessential cruise port, is the bustling busy bee of the trio. In addition to its natural charms, St. Thomas is also a duty-free shopping mecca.

St. Croix, 40 miles south, is an island on the move. Its history of agriculture has left sugar mills and plantations to visit, and there is an ever-increasing number of heritage trails to follow.

St. John is the natural one: Two-thirds of the island is a national park.

The USVI is east of Puerto Rico in the Caribbean. St. Thomas is 75 miles/120 kilometers east of Puerto Rico and is 32 square miles/83 square kilometers. St. John is 4 miles/6.5 kilometers east of St. Thomas and 7 miles/11 kilometers west of Tortola in the British Virgin Islands.

At 212 square miles, the USVI is twice the size of Washington D.C. St. Croix is the largest of the islands, followed by St. Thomas and St. John.

The wreck of the WIT Shoalis more than 300 ft long and sits upright in 90 ft of water with the wheelhouse at only 25ft. The ship was a tank transport vessel in WW II and has five decks to explore. Carval Rock in St John is an advanced dive because of the strong currents and seasonal North swell but divers can circumnavigate the entire submerged formation with sponge and coral covered caverns. St John is also home to Grass and Mingo Cays, two enormous fringing reefs that gently slope from 10 to 60 ft. Sail Rock soars 125 ft out of the water and has three pinnacles just beneath the surface that drop to 90 ft. Salt River East and West, at the mouth of Salt River Bay, are separated by a deep chasm. Salt River West is closer to shore and starts at 20 ft dropping to 90. Salt River East drops vertically at the mooring line starting at about 40 feet and can be explored to safe diving depth limits.

Topography: Most of the Virgin Islands (U.S. and British) were formed by volcanic activity during a series of violent underwater explosions millions of years ago. From the floor of the sea, volcanic eruptions created peaks and mountain chains that became Caribbean islands. St. Thomas and St. John have steep hills, low valleys and craggy coastlines. St. Croix is the exception. Created by conventional plate drift and folding, it is less rugged, with sloping hills and a gentle coastline.

Climate: Subtropical. Year-round average daytime temperature is about 78F/26C with easterly trade winds to help keep things comfortable. Seasonal temperatures fluctuate less than 10F/6C. The widest temperature change occurs with elevation (for every incline of 300 feet/98meters, there's about a 10F/.6C drop in temperature.) Day-to-night temperatures can drop approximately 10F/6C. Average annual rainfall is only 50 inches/1,270 millimeters and occurs in late spring and late summer.