The US Virgin Islands (USVI ) in the northeastern Caribbean, consist of St. Croix (207 km2), St. Thomas (83 km2), St. John (52 km2) and numerous smaller islands (Dammann and Nellis 1992). They are part of the Lesser Antilles and Leeward Islands on the eastern boundary of the Caribbean plate (Fig. 8.1). An extensive platform underlies St. Thomas and St. John and connects these islands to Puerto Rico and the British Virgin Islands. This platform extends about 32 km north of the islands and then slopes gradually to depths of over 300 m and eventually descends into the 8,000 m deep Puerto Rican Trench. South of the islands, the platform extends about 13 km and then abruptly drops off to over 4,000 m. St. Croix, about 60 km to the south, is on a separate platform which is much shallower than the northern Virgin Islands’ platform and extends less than 5 km from shore except on the east end of the island. The deepest part of the Virgin Islands Trough that separates St. Thomas and St. John from St. Croix is 4,200 m.

The authors have used color stereo photos along with a three-dimensional visualization photogrammetric software package, Socet Set, to produce orthophotometric-corrected mosaics of St. Croix, St. John, and St. Thomas in the U.S. Virgin Islands. These mosaics are used for numerous applications such as characterization of the shallow water benthic habitat, terrestrial habitat characterizations, and development planning. Examples of the mosaics and products derived from the mosaics will be shown along with accuracy assessments and verification results