Figure 68. (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 4 is highlighted. (B) Index map shows locations of named reefs and shoals in the upper Keys and northeastern middle Keys, delineated by dashed lines. Red rectangles show geographic boundaries of Tiles 1, 2, 3, and 4, with Tile 4 and its geographic sites highlighted. Sanctuary boundary is in red; shelf-margin contour (blue) is in meters.