Figure 97. (A) Landsat satellite image of south Florida shows individual tile boundaries (blue rectangles) of this regional study in the Florida Keys National Marine Sanctuary. Tile 7/8 is highlighted. (B) Index map shows locations of named reefs and shoals in the upper Keys and northeastern middle Keys, delineated by dashed lines. Most named reefs and shoals were once historic islands. Red rectangles show geographic boundaries of Tiles 1, 2, 3, and 4. (C) Contiguous part of index map shows westernmost part of middle Keys and the lower Keys (dashed lines). Red rectangles show geographic boundaries of Tiles 5, 6, 7, and 8, with Tile 7/8 (here considered a single tile) and its geographic sites highlighted. Black-dot rectangle shows area of Key West National Wildlife Refuge. Sanctuary boundary is in red; shelf-margin contour is in blue. Contours are in meters.