U.S. Geological Survey Open-File Report 2004-1416, Coastal Vulnerability Assessment of Dry Tortugas National Park (DRTO) to Sea-Level Rise , Figure 2, Shoreline segments for the Dry Tortugas.

Coastal Vulnerability Assessment of Dry Tortugas National Park (DRTO) to Sea-Level Rise
USGS Open-File Report 2004-1416

Figure 2. Shoreline segments for the Dry Tortugas. All of the islands were divided into two shoreline segments with the exception of middle key.