Geography of St. John
Geographically speaking, St. John can be classified as belonging to the following island groups: What do these classifications mean?
The West Indies
St. John is part of a mostly underwater mountain plateau called the Puerto Rican Bank. This plateau, or shelf, extends from Puerto Rico on the west to Anegada and the Anegada reef on the east. The highest sections of this plateau rise above the sea to form Puerto Rico, Vieques, Culebra, and the American and British Virgin Islands with the exception of St Croix. The lower areas of the shelf lie under relatively shallow water, seldom more than 180 feet deep. In fact, during the last ice age, about 20,000 years ago, when the depth of the Earth's oceans was two to three hundred feet lower than it is today, the entire bank was above water and constituted one large island.
St. Croix is technically not part of the Greater Antilles because it is separated from the Puerto Rican Bank by extremely deep water.
Although geographically part of the Greater Antilles, the Virgin Islands are comparable in size to the Lesser Antilles and are not far from the northern end of this island group, separated only by the relatively narrow Anegada Passage. Moreover, historically, culturally, linguistically and politically, the Virgin Islands have more in common with the islands of the Lesser Antilles than with the Greater Antilles.
The United States
Until the Americans changed the name of the Danish West Indies, what is today called the British Virgin Islands were simply, the Virgin Islands. To avoid confusion after the 1917 purchase, the English renamed their Caribbean colony, the British Virgin Islands."