Editing H. L. Hunley (section)

== Disappearance ==

After the attack, ''H.L. Hunley'' failed to return to her base. At one point, there appeared to be evidence that ''Hunley'' survived as long as one hour following the attack, which occurred at about 20:45. The day after the attack, the commander of "Battery Marshall" reported that he had received "the signals" from the submarine indicating she was returning to her base.<ref>''The Official Records of the Union and Confederate Navies in the War of the Rebellion''; Series I – Vol. 15, p. 335.</ref> The report did not say what the signals were. A postwar correspondent wrote that "two blue lights" were the prearranged signals,<ref>{{cite book |first=Jacob N. |last=Cardozo |title=Reminiscences of Charleston |location=Charleston |year=1866 |page=124}}</ref> and a lookout on ''Housatonic'' reported he saw a "blue light" on the water after his ship sank.<ref>''Proceedings of the Naval Court of Inquiry on the Sinking of the Housatonic '' NARA Microfilm Publication M 273, reel 169, Records of the Judge Advocate General (Navy) Record Group 125</ref> "Blue light" in 1864 referred to a [[Blue light (pyrotechnic signal)|pyrotechnic signal]]<ref>{{cite book |first=Noah |last=Webster |author-link=Noah Webster |title=International Dictionary of the English Language Comprising the issues of 1864, 1879 and 1884 |editor-first=Noah |editor-last=Porter |editor-link=Noah Porter |page=137}}</ref> in long use by the U.S. Navy.<ref>{{cite book |first=George |last=Marshall |title=Marshall's Practical Marine Gunnery: Containing a View of the Magnitude, Weight, Description and Use of Every Article Used in the Sea Gunner's Department in the Navy of the United States |location=Norfolk |year=1822 |pages=22, 24}}</ref> It has been falsely represented in published works as a blue lantern; the lantern eventually found on the recovered ''H. L. Hunley'' had a clear, not a blue, lens.<ref name="Chaffin2010">{{cite book |first=Tom |last=Chaffin |title=The H. L. Hunley: The Secret Hope of the Confederacy |url=https://books.google.com/books?id=pQcjlDMjXFoC |date=16 February 2010 |publisher=Farrar, Straus and Giroux |isbn=978-1-4299-9035-6 |pages=225–242}}</ref> Pyrotechnic "blue light" could be seen easily over the {{convert|4|mi|adj=on|spell=in|sigfig=1}} distance between Battery Marshall and the site of ''Hunley''{{'}}s attack on ''Housatonic''.<ref>{{cite book |last1=Benton |first1=Captain James Gilchrist |title=A Course of Instruction in Ordnance and Gunnery Compiled for the Use of the Cadets of the United States Military Academy |date=1862 |page=[https://archive.org/details/courseofinstruct00bentrich/page/369 369] |publisher=New York, Van Nostrand |edition=Second |url=https://archive.org/details/courseofinstruct00bentrich}}</ref>

After signaling, Dixon's plan could have been to take his submarine underwater to make a return to Sullivan's Island, although he left no confirmed documentation of this plan. At one point, the finders of ''Hunley'' suggested she was unintentionally rammed by USS ''Canandaigua'' when that [[warship]] was going to rescue the crew of ''Housatonic'', but no such damage was found when she was raised from the bottom of the harbor. Instead, all evidence and analysis eventually pointed to the instantaneous death of ''Hunley''{{'}}s entire crew at the moment of the spar torpedo's contact with the hull of ''Housatonic''. Upon removal of the silt inside the hull, the skeletons of the crewmembers were found seated at their stations with no signs of skeletal trauma.<ref name=":1">{{cite book |last=Lance |first=Rachel |author-link=Rachel Lance |url=https://www.worldcat.org/oclc/1103534885 |title=In the waves : my quest to solve the mystery of a Civil War submarine |year=2020 |isbn=978-1-5247-4415-1 |location=[[New York, New York]] |oclc=1103534885}}</ref> In October 2008, scientists reported they had found that the crew of ''Hunley'' had not set her pump to remove water from the crew's compartment, and this might indicate she was not flooded until after they died. In January 2013, it was announced that conservator Paul Mardikian had found evidence of a copper sleeve at the end of ''Hunley''{{'}}s spar. This finding indicated the torpedo had been attached directly to the [[Spar (sailing)|spar]], meaning the submarine may have been less than {{convert|16|ft|m|sigfig=1|abbr=}} from ''Housatonic'' when the torpedo exploded.<ref name="Smith"/><ref>{{cite web |last=Lance |first=Rachel |author-link=Rachel Lance |title=The New Explosive Theory About What Doomed the Crew of the 'Hunley' |url=https://www.smithsonianmag.com/history/new-explosive-theory-what-doomed-crew-hunley-180974159/ |access-date=2020-10-12 |website=Smithsonian Magazine |language=en}}</ref> In 2018, researchers reported that the [[keel block]]s, which the crew could release from inside the vessel to allow the sub to surface quickly in an emergency, had never been released.<ref>{{cite news |date=July 18, 2018 |title=Clues to Confederate Mystery: Sub's Crew Never Dumped Weight |newspaper=[[New York Times]] |agency=Associated Press |url=https://www.nytimes.com/aponline/2018/07/18/us/ap-us-confederate-submarine.html}}</ref>

The short distance between the torpedo and the vessel, in addition to the signs that the crew died instantaneously and without a struggle to survive, led a team of blast trauma specialists from Duke University to theorize that the ''Hunley''{{'}}s crew was killed by the [[blast injury|blast itself]],<ref name=":0" /> which could have transmitted pressure waves inside the vessel without damaging its hull. Their research, which included scaled experiments with live black powder bombs, provided data indicating the crew was likely killed by the explosion of their own torpedo, which could have caused immediate pulmonary blast trauma. The Duke team's experiments and results were published August 2017 in the peer-reviewed journal ''PLoS One''<ref name=":0" /> and eventually became the subject of the book ''In the Waves: My Quest to Solve the Mystery of a Civil War Submarine''.<ref name=":1" /> Although their conclusions have been disputed by archaeologists with the [[Naval History and Heritage Command|Naval History and Heritage Command (NHHC)]], the NHCC website<ref name=":2">{{cite web |date=28 August 2017 |title=Black Powder Blast Effects on the Confederate Submarine Hunley |url=https://www.history.navy.mil/research/underwater-archaeology/sites-and-projects/ship-wrecksites/hl-hunley/black-powder-blast-effects-hunley.html |access-date=2018-03-14 |website=Naval History and Heritage Command}}</ref> disputing the results of the scientific experiments contains several inconsistencies. For example, the website implies that the experiments are not valid because "a 1/8th inch plate at 1/6th scale is only 0.02 inches thick," but neither of these dimensions is relevant to either the original ''Hunley'' or the scale model used by Duke.<ref name=":2" /><ref name=":0" /><ref>{{Cite web |last=Daley |first=Jason |date=July 23, 2018 |title=New Clues About Why the Confederate Submarine H.L. Hunley Sank |url=https://www.smithsonianmag.com/smart-news/new-clues-about-why-confederate-submarine-hl-hunley-sank-180969724/ |access-date=October 16, 2023 |website=Smithsonian Magazine}}</ref>

Years after ''Hunley'' went missing, when the area around the wreck of ''Housatonic'' was surveyed, the sunken ''Hunley'' was found on the seaward side of the sloop, where no one had considered looking before. This later indicated that the ocean current was going out following the attack on ''Housatonic'', taking ''Hunley'' with her to where she was eventually found and later recovered.{{Citation needed|date=October 2023}}