The Superior Shoal is a geologic shoal of approximately 20 square miles (52 km2) located 50 miles (80 km) north of Copper Harbor, Michigan in the middle of Lake Superior whose highest point lies only 21 feet (6.4 m) below the lake's surface.[1] The shoal is a volcanic hump in an otherwise deep part of the lake, and though fishermen had known of its existence for generations it was only officially charted in 1929.[2]:193 It has been theorized that the World War I Inkerman and Cerisoles Minesweepers, which disappeared during their maiden voyage on Lake Superior in mid November 1918, may have run aground on this shoal[2]:192 and some have theorized that it may have been to blame for the November 10, 1975 sinking of the SS Edmund Fitzgerald,[3] and the November 21, 1902 disappearance of the Bannockburn, the "Flying Dutchman of the Great Lakes", as well. It is one of the known off-shore spawning and foraging habitats for the juvenile lean lake trout.[4]
A different shoal with the same name is located just off Delf Island in Georgian Bay east of Lake Huron in Ontario[5]