The Monitor National Marine Sanctuary (sanctuary) was designated the nation's first national marine sanctuary in 1975. The site protects the wreck of the famed Civil War ironclad USS Monitor. It is located approximately 16 miles southeast of Cape Hatteras, North Carolina, where it sank in a storm while under tow on December 31, 1862, with the loss of sixteen sailors. The sanctuary consists of a column of water one mile in diameter extending from the seabed to the surface, surrounding the shipwreck. NOAA is reviewing the sanctuary boundaries in order to evaluate the benefits, need and impact of expanding the sanctuary's boundaries to include additional submerged maritime cultural resources as described in the February 2013 Monitor National Marine Sanctuary Final Management Plan and Environmental Assessment. The Monitor National Marine Sanctuary Advisory Council recommended that the Office of National Marine Sanctuaries evaluate an expansion of existing boundaries to protect, manage, and interpret additional historic shipwrecks and other potential maritime heritage resources that are located or believed to be located in the adjacent waters of North Carolina in an area known as the "Graveyard of the Atlantic." On January 8, 2016, NOAA issued a notice of intent regarding expanding the sanctuary and asked for public comments.