two documentary films; the first was an episode of the "Sea Hunters" that aired on National Geographic International Television in 2004, and the second, by Der Spiegel, which aired in Europe and in the US on the Smithsonian channel in 2010. See also H. L. Hunley (submarine) Alligator (submarine) References External links Shipwrecks in the Pacific Ocean 19th-century submarines of the United States 1865 ships Ships built in Brooklyn Hand-cranked submarines Historic American Engineering Record in the former Panama Canal Zone History of underwater diving Diving equipment