It extends roughly 230 km (120 nmi; 140 mi) from Fowey Rocks, off Key Biscayne, to Sand Key, off Key West. Its width ranges from approximately 10 km (5.4 nmi; 6.2 mi) to 0.40 km (1⁄4 mi) wide at its narrowest part.[5][6] It varies in depth from 7 to 8 m (23 to 26 ft) off the Upper Keys along the center of the channel to 12 to 15 m (39 to 49 ft) off the Middle and Lower Keys. A course in Hawk Channel roughly 3.2 km (2 mi) offshore is partially protected by the deepwater of the Straits of Florida and allows vessels drawing roughly 2.1 to 3.0 m (7 to 10 ft) to avoid the adverse currents of the Gulf Stream while crossing through the Keys.[7][8][9]
^Williams, John Lee (1837). The Territory of Florida: Or Sketches of the Topography, Civil and Natural History, of the Country, the Climate, and the Indian Tribes, from the First Discovery to the Present Time (Digitized ed.). A. T. Goodrich. p. 40.
^Porter, James; Porter, Karen G. (2001). The Everglades, Florida Bay, and Coral Reefs of the Florida Keys. CRC Press. pp. 354–772. ISBN9781420039412.
^Reilly, Benjamin (2005). Tropical Surge: A History of Ambition and Disaster on the Florida Shore. Pineapple Press. p. 36. ISBN9781561643301.
^and Geodetic Survey, U.S. Coast (1913). Table of Depths for Channels and Harbors Coasts of the U.S. Including Porto Rico ... and the Philippine Islands (Digitized ed.). p. 162.