Editing Submarine (section)

==History==
{{Main|History of submarines}}

=== Etymology ===
The word ''submarine'' means 'underwater' or 'under-sea' (as in [[submarine canyon]], [[submarine pipeline]]) though as a noun it generally refers to a vessel that can travel underwater.<ref>[https://www.oed.com/view/Entry/192795?rskey=sQhrJW&result=1&isAdvanced=false#eid ''Submarine''] at [[OED]]; retrieved 4 September 2021</ref> The term is a contraction of ''submarine boat''<ref>[https://www.oed.com/view/Entry/192795?redirectedFrom=submarine+boat#eid227775172 ''Submarine boat''] at [[OED]]; retrieved 4 September 2021</ref><ref>''The New Shorter Oxford English Dictionary'', Clarendon Press, Oxford, 1993, Vol. 2 N–Z</ref> and occurs as such in several languages, e.g. French ({{lang|fr|sous-marin}}), and Spanish ({{lang|es|submarino}}), although others retain the original term, such as Dutch ({{lang|nl|Onderzeeboot}}), German ({{lang|de|Unterseeboot}}), Swedish ({{lang|sv|Undervattensbåt}}), and Russian ({{lang|ru|подводная лодка}}: {{transliteration|ru|podvodnaya lodka}}), all of which mean 'submarine boat'. By [[naval tradition]], submarines are usually referred to as ''boats'' rather than as ''ships'', regardless of their size.<ref name="cutler"/> Although referred to informally as ''boats'',<ref>{{Cite book |url=https://books.google.com/books?id=Zo0LzmyjP-4C&q=boat |title=Blind Man's Bluff: The Untold Story Of American Submarine Espionage |last1=Sontag |first1=Sherry |last2=Drew |first2=Christopher |last3=Drew |first3=Annette Lawrence |date=19 October 1998 |publisher=PublicAffairs |isbn=9781891620089 |language=en}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=qU4rAQAAQBAJ&q=boat |title=Stealth Boat: Fighting the Cold War in a Fast Attack Submarine |last=McHale |first=Gannon |date=15 September 2013 |publisher=Naval Institute Press |isbn=9781612513461 |language=en}}</ref> U.S. submarines employ the designation USS ([[United States Ship]]) at the beginning of their names, such as {{USS|Alabama|SSBN-731 |6}}. In the Royal Navy, the designation HMS can refer to "His Majesty's Ship" or "His Majesty's Submarine", though the latter is sometimes rendered "HMS/m".<ref>[https://acronyms.thefreedictionary.com/HMS%2FM ''HMS/m''] at acronyms.thefreedictionary; retrieved 4 September 2021</ref><ref group=Note>For example, see [https://www.iwm.org.uk/collections/item/object/205160540 HMS/m ''Tireless''], at [[Imperial War Museum|IWM]], [https://historicengland.org.uk/listing/the-list/list-entry/1000043 HMS/m ''A.1''] at [[Historic England]]</ref> Submarines are generally referred to as ''boats'' rather than ''ships''.<ref group="Note">The Submarine service page on the official website of the Royal Navy refers to "These powerful boats"[https://www.royalnavy.mod.uk/the-equipment/submarines], and in at a speech in Washington, Adm. Sir Philip Jones announced "that the name ''Dreadnought'' will return as lead boat and class name" for [[Dreadnought-class submarine|Britain's latest ballistic missile submarines]].[https://www.royalnavy.mod.uk/news-and-latest-activity/news/2016/october/22/161022-first-sea-lord-trafalgar-night-speech-in-washington]</ref>

===Early human-powered submersibles===
[[File:Van Drebbel.jpg|thumb|An early submersible craft, built by [[Cornelis Drebbel]], propelled by oars]]

====16th and 17th centuries====
According to a report in ''Opusculum [[Jean Taisnier|Taisnieri]]'' published in 1562:<ref>Joann Taisnier Hannon ([[Jean Taisnier]] (1508–1562)), ''Opusculum perpetua memoria dignissimum, de natura magnetis et eius effectibus'' [Most fitting work in perpetual remembrance, on the nature of the magnet and its effects] (Köln (Cologne, "Colonia"), (Germany): Johann Birckmann, 1562), pp. 43–45.  Available from: [https://bildsuche.digitale-sammlungen.de/index.html?c=viewer&bandnummer=bsb00022856&pimage=49&v=100&nav=&l=en Bavarian State Library] From p. 43: ''"Ne autem Lector nostra dicta videatur refutare, arbitratus ea, quae miracula putat, naturae limites excedere, unica demonstratione elucidabo, quomodo scilicet quis in fundum alicuius aquae aut fluvij, sicco corpore intrare possit, quod me vidisse in celebri Oppido & Regno Tolleti affirmavi, coram piae memoriae Carolo Quinto Imperatore, & infinitis aliis spectatoribus."'' (Nevertheless, reader, our statement is seen to refute something witnessed, which one considers a wonder, exceeding the limits of nature; I will elucidate a unique demonstration, namely, how one can penetrate to the bottom of any water or river while remaining dry, which, I assert, I saw in the celebrated city and kingdom of Toledo in the presence of Emperor Charles V of blessed memory and a multitude of other spectators.) From p. 44: ''"Nunc venio ad experientiam praedictam, Tolleti demonstratam a duobus Graecis, qui Cacabo magnae amplitudinis accepto, orificio inverso, funibus in aere pendente, tabem & asseres in medio concavi Cacabi affigunt, ... "'' (Now I come to the experiment mentioned above: in Toledo, it was shown by two Greeks, who, I understand, attached to a cauldron (''cacabus'') of great size — [which had its] opening inverted [and which was] held in the air by ropes — a beam and poles inside of the hollow cauldron ... [The beam and poles formed seats for the divers.]) The German Jesuit scientist [[Gaspar Schott]] (1608–1666) quoted Taisnier's account and mentioned that Taisnier had witnessed the demonstration in 1538.  Gaspar Schott, ''Technica Curiosa, sive Mirabilia Artis, Libris XII. ... '' [Curious works of skill, or marvelous works of craftsmanship, in 12 books ... ] (Nuremberg (Norimberga), (Germany): Johannes Andreas Endter & Wolfgang Endter, 1664), ''Liber VI: Mirabilium Mechanicorum'' (Book 6: Wonders of mechanics), [https://books.google.com/books?id=dhRTAAAAcAAJ&q=icon&pg=PA393 p. 393.] From p. 393: ''" ... quod nihilominus Anno 1538 in Hispaniae oppido Toleto &c. coram piae memoriae Carolo V. Imperatore, cum decem propemodum millibus hominum experientia vidi."'' ( ... that nevertheless I saw the experiment in the year 1538 in Spain in the city of Toledo, etc., in the presence of Emperor Charles V of blessed memory, with almost ten thousand people.)</ref>
{{blockquote|Two Greeks submerged and surfaced in the river [[Tagus]] near the City of [[Toledo, Spain|Toledo]] several times in the presence of [[Charles V, Holy Roman Emperor|The Holy Roman Emperor Charles V]], without getting wet and with the flame they carried in their hands still alight.<ref>{{cite web|url=http://hemeroteca.abc.es/nav/Navigate.exe/hemeroteca/madrid/abc/1980/03/07/089.html|title=Espańa, Precursora de la Navegación Submarina|archive-url=https://web.archive.org/web/20150721145006/http://hemeroteca.abc.es/nav/Navigate.exe/hemeroteca/madrid/abc/1980/03/07/089.html|archive-date=July 21, 2015|url-status=live|date=March 7, 1980|work=[[ABC (newspaper)|ABC]]}}</ref>}}

In 1578, the English mathematician [[William Bourne (mathematician)|William Bourne]] recorded in his book ''Inventions or Devises'' one of the first plans for an underwater navigation vehicle.<ref>Delgado (2011), p. 13.</ref> A few years later the Scottish mathematician and theologian [[John Napier]] wrote in his ''Secret Inventions'' (1596) that "These inventions besides devises of sayling under water with divers other devises and strategems for harming of the enemyes by the Grace of God and worke of expert Craftsmen I hope to perform." It is unclear whether he carried out his idea.<ref name = Tiere/>

[[Jerónimo de Ayanz y Beaumont]] (1553–1613) created detailed designs for two types of air-renovated submersible vehicles. They were equipped with oars, autonomous floating snorkels worked by inner pumps, portholes and gloves used for the crew to manipulate underwater objects. Ayanaz planned to use them for warfare, using them to approach enemy ships undetected and set up timed gunpowder charges on their hulls.<ref>{{cite web|url=https://www.xataka.com/historia-tecnologica/jeronimo-ayanz-da-vinci-olvidado-que-diseno-submarino-sistemas-aire-acondicionado-espana-austrias|title=Jerónimo de Ayanz, el Da Vinci olvidado que diseñó un submarino y sistemas de aire acondicionado en la España de los Austrias|date=September 26, 2021|access-date=October 17, 2022|publisher=Xataka|language=Spanish}}</ref>

The first submersible of whose construction there exists reliable information was designed and built in 1620 by [[Cornelis Drebbel]], a Dutchman in the service of [[James VI and I|James I of England]]. It was propelled by means of oars.<ref name = Tiere>{{Citation|last=Tierie|first=Gerrit|title=Cornelis Drebbel (1572–1633)|type=Thesis|publisher=Rijksuniversiteit te Leiden|place=Amsterdam|pages=92|date=10 June 1932|language=en|url=http://www.drebbel.net/Tierie.pdf}}</ref>

====18th century====
By the mid-18th century, over a dozen patents for submarines/submersible boats had been granted in England. In 1747, Nathaniel Symons patented and built the first known working example of the use of a ballast tank for submersion. His design used leather bags that could fill with water to submerge the craft. A mechanism was used to twist the water out of the bags and cause the boat to resurface. In 1749, the [[Gentlemen's Magazine]] reported that a similar design had initially been proposed by [[Giovanni Borelli]] in 1680. Further design improvement stagnated for over a century, until application of new technologies for propulsion and stability.<ref name="vector">{{cite web|url=http://inventors.about.com/od/sstartinventions/a/Submarines.htm|archive-url=https://archive.today/20120709102159/http://inventors.about.com/od/sstartinventions/a/Submarines.htm|url-status=dead|archive-date=July 9, 2012|title=The Invention Of The Submarine|author=Mary Bellis|access-date=16 April 2014}}</ref>

The first military submersible was {{ship||Turtle|submersible|2}} (1775), a hand-powered acorn-shaped device designed by the American [[David Bushnell (inventor)|David Bushnell]] to accommodate a single person.<ref>{{cite web|title=The Submarine Turtle: Naval Documents of the Revolutionary War |url=http://www.history.navy.mil/library/online/sub_turtle.htm |archive-url=https://web.archive.org/web/20080917024301/http://www.history.navy.mil/library/online/sub_turtle.htm |url-status=dead |archive-date=17 September 2008 |publisher=Navy Department Library |access-date=21 May 2013 }}</ref> It was the first verified submarine capable of independent underwater operation and movement, and the first to use [[Propeller|screws]] for propulsion.<ref>[https://web.archive.org/web/20030415051537/http://web.mit.edu/invent/iow/bushnelld.html Inventor of the Week: Archive]. mit.edu</ref>

====19th century====
[[File:Fulton's submarine design.jpg|alt=Illustration by Robert Fulton showing a "plunging boat"|thumb|1806 illustration by Robert Fulton showing a "plunging boat"]]

In 1800, France built {{ship||Nautilus|1800 submarine|2}}, a human-powered submarine designed by American [[Robert Fulton]]. They gave up on the experiment in 1804, as did the British, when they reconsidered Fulton's submarine design.

In 1850, [[Wilhelm Bauer]]'s {{ship||Brandtaucher}} was built in Germany. It remains the oldest known surviving submarine in the world.<ref>{{cite book |last=Delgado |first=James P. |url=https://books.google.com/books?id=8ue6CwAAQBAJ&pg=PA224|title=Silent Killers: Submarines and Underwater Warfare|publisher=Bloomsbury Publishing|date=2011|page=224|isbn=9781849088602}}</ref>

In 1864, late in the [[American Civil War]], the [[Confederate navy]]'s {{ship||H. L. Hunley|submarine|2}} became the first military submarine to sink an enemy vessel, the Union [[sloop-of-war]] {{USS|Housatonic|1861|6}}, using a gun-powder-filled keg on a spar as a torpedo charge. The ''Hunley'' also sank. The explosion's shock waves may have killed its crew instantly, preventing them from pumping the bilge or propelling the submarine.<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=24 November 2020 |website=Smithsonian Magazine |language=en}}</ref>

In 1866, {{ship||Sub Marine Explorer}} was the first submarine to successfully dive, cruise underwater, and resurface under the crew's control. The design by German American [[Julius H. Kroehl]] (in German, ''Kröhl'') incorporated elements that are still used in modern submarines.<ref>{{cite journal|author=James P. Delgado|title=Archaeological Reconnaissance of the 1865 American-Built Sub Marine Explorer at Isla San Telmo, Archipielago de las Perlas, Panama|journal=International Journal of Nautical Archaeology Journal|volume=35|issue=2|pages=230–252|year=2006|doi=10.1111/j.1095-9270.2006.00100.x|bibcode=2006IJNAr..35..230D |s2cid=162403756|author-link=James P. Delgado|issn = 1057-2414}}</ref>

In 1866, {{ship||Flach|submarine|2}} was built at the Chilean government's request by [[Karl Flach]], a German engineer and immigrant. It was the fifth submarine built in the world<ref>{{cite news |title=Recovering Chile's 19th Century Shipwrecks in Valparaiso's Port |date=25 November 2006 |url=http://www.tcgnews.com/santiagotimes/index.php?nav=story&story_id=12293&topic_id=1 |work=The Santiago Times |access-date=17 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20080124142651/http://www.tcgnews.com/santiagotimes/index.php?nav=story&story_id=12293&topic_id=1 |archive-date=24 January 2008 }}</ref> and, along with a second submarine, was intended to defend the port of [[Valparaiso]] against attack by the [[Spanish Navy]] during the [[Chincha Islands War]].

===Mechanically powered submarines===
Submarines could not be put into widespread or routine service use by navies until suitable engines were developed. The era from 1863 to 1904 marked a pivotal time in submarine development, and several important technologies appeared. A number of nations built and used submarines. [[Diesel–electric transmission|Diesel electric]] propulsion became the dominant power system and equipment such as the periscope became standardized. Countries conducted many experiments on effective tactics and weapons for submarines, which led to their large impact in [[World War I]].

====1863–1904====
[[File:Plongeur.jpg|thumb|upright=1.3|left|The French submarine [[French submarine Plongeur|''Plongeur'']]]]

The first submarine not relying on human power for propulsion was the French {{ship|French submarine|Plongeur||2}} (''Diver''), launched in 1863, which used compressed air at {{cvt|180|psi|disp=flip|lk=on}}.{{citation needed|date=December 2022}} [[Narcis Monturiol i Estarriol|Narcís Monturiol]] designed the first [[air-independent power|air-independent]] and [[combustion]]-powered submarine, {{ship||Ictíneo II}}, which was launched in [[Barcelona]], Spain in 1864.

The submarine became feasible as potential weapon with the development of the [[Whitehead torpedo]], designed in 1866 by British engineer [[Robert Whitehead (engineer)|Robert Whitehead]], the first practical [[self-propelled torpedo]].<ref>{{cite web|title=Torpedo History: Whitehead Torpedo Mk1|url=http://www.history.navy.mil/museums/keyport/html/part2.htm|publisher=Naval History and Heritage Command|access-date=28 May 2013|archive-date=15 September 2014|archive-url=https://web.archive.org/web/20140915054904/http://www.history.navy.mil/museums/keyport/html/part2.htm|url-status=dead}}</ref> The [[spar torpedo]] that had been developed earlier by the Confederate States Navy was considered to be impracticable, as it was believed to have sunk both its intended target, and ''H. L. Hunley'', the submarine that deployed it.

The Irish inventor [[John Philip Holland]] built a model submarine in 1876 and in 1878 demonstrated the [[Holland I]] prototype. This was followed by a number of unsuccessful designs. In 1896, he designed the Holland Type VI submarine, which used internal combustion engine power on the surface and electric [[battery (electricity)|battery]] power underwater. Launched on 17 May 1897 at Navy Lt. [[Lewis Nixon (naval architect)|Lewis Nixon]]'s [[Crescent Shipyard]] in [[Elizabeth, New Jersey]], ''Holland VI'' was purchased by the [[United States Navy]] on 11 April 1900, becoming the Navy's first commissioned submarine, christened {{USS|Holland|SS-1|6}}.<ref>{{cite encyclopedia |url=http://www.britannica.com/eb/article-9040797/John-Philip-Holland |title=John Philip Holland |encyclopedia=Encyclopædia Britannica |access-date=1 April 2015}}</ref>

Discussions between the English clergyman and inventor [[George Garrett (inventor)|George Garrett]] and the Swedish industrialist [[Thorsten Nordenfelt]] led to the first practical steam-powered submarines, armed with torpedoes and ready for military use. The first was ''Nordenfelt I'', a 56-tonne, {{convert|19.5|m|ft|adj=on}} vessel similar to Garrett's ill-fated {{ship||Resurgam}} (1879), with a range of {{convert|240|km|nmi mi}}, armed with a single [[torpedo]], in 1885.

[[File:Peral1888.jpg|thumb|''[[Spanish submarine Peral|Peral]]'' at [[Cartagena, Spain|Cartagena]], 1888]]
A reliable means of propulsion for the submerged vessel was only made possible in the 1880s with the advent of the necessary electric battery technology. The first electrically powered boats were built by [[Isaac Peral y Caballero]] in Spain (who built {{ship|Spanish submarine|Peral||2}}), [[Henri Dupuy de Lôme|Dupuy de Lôme]] (who built {{ship|French submarine|Gymnote|Q1|2}}) and [[Gustave Zédé]] (who built [[French submarine Gustave Zédé (1893)|''Sirène'']]) in France, and James Franklin Waddington (who built ''Porpoise'') in England.<ref>{{cite book|url=https://books.google.com/books?id=ohYiAQAAIAAJ|title=The Garrett Enigma and the Early Submarine Pioneers|first=Paul |last=Bowers|year=1999|publisher=Airlife|page=167|isbn=978-1-84037-066-9}}</ref> Peral's design featured torpedoes and other systems that later became standard in submarines.<ref>{{Cite news|url=http://www.elmundo.es/elmundo/2013/08/14/ciencia/1376474198.html|title=Isaac Peral, el genio frustrado|last=Sanmateo|first=Javier|date=5 September 2013|work=El Mundo|access-date=12 December 2017|language=es}}</ref><ref>{{Cite book|title=Silent Killers: Submarines and Underwater Warfare|last1=Delgado|first1=James P.|last2=Cussler|first2=Clive|publisher=Bloomsbury Publishing|year=2011|isbn=978-1849088602|pages=89}}</ref>

[[File:USS Plunger - NH 85735 - cropped.jpg|thumb|{{USS|Plunger|SS-2|6}}, launched in 1902]]
[[File:Akula&Ryurik1913.jpg|thumb|{{ship|Russian submarine|Akula|1908|2}} (launched in 1907) was the first Russian submarine able to cruise long distances.]]
Commissioned in June 1900, the French steam and electric {{ship|French submarine|Narval|Q4|2}} employed the now typical double-hull design, with a pressure hull inside the outer shell. These 200-ton ships had a range of over {{cvt|100|mi|disp=flip}} underwater. The French submarine [[French submarine Aigrette|''Aigrette'']] in 1904 further improved the concept by using a diesel rather than a gasoline engine for surface power. Large numbers of these submarines were built, with seventy-six completed before 1914.

The Royal Navy commissioned five {{sclass2|Holland|submarine|2}}s from [[Vickers]], [[Barrow-in-Furness]], under licence from the [[Holland Torpedo Boat Company]] from 1901 to 1903. Construction of the boats took longer than anticipated, with the first only ready for a diving trial at sea on 6 April 1902. Although the design had been purchased entirely from the US company, the actual design used was an untested improvement to the original Holland design using a new {{convert|180|hp}} petrol engine.<ref>Galantin, Ignatius J., Admiral, USN (Ret.). Foreword to ''Submariner'' by Johnnie Coote, p. 1</ref>

These types of submarines were first used during the [[Russo-Japanese War]] of 1904–05. Due to the blockade at [[Port Arthur, China|Port Arthur]], the Russians sent their submarines to [[Vladivostok]], where by 1 January 1905 there were seven boats, enough to create the world's first "operational submarine fleet". The new submarine fleet began patrols on 14 February, usually lasting for about 24 hours each. The first confrontation with Japanese warships occurred on 29 April 1905 when the Russian submarine [[Som-class submarine|''Som'']] was fired upon by Japanese torpedo boats, but then withdrew.<ref>Olender p. 175</ref>

====World War I====
[[File:U9Submarine.jpg|thumb|left|The German submarine {{SMU|U-9}}, which sank three British [[cruiser]]s in [[Action of 22 September 1914|less than an hour in September 1914]]]]

Military submarines first made a significant impact in [[World War I]]. Forces such as the [[U-boat]]s of Germany saw action in the [[First Battle of the Atlantic]], and were responsible for sinking {{RMS|Lusitania}}, which was sunk as a result of [[unrestricted submarine warfare]] and is often cited among the reasons for the entry of the United States into the war.<ref>{{cite book|title=Germany and the Americas|author=Thomas Adam|page=1155}}</ref>

At the outbreak of the war, Germany had only twenty submarines available for combat, although these included vessels of the diesel-engined ''[[SM U-19 (Germany)|U-19]]'' class, which had a sufficient range of {{convert|5000|mi|km|sigfig=1}} and speed of {{convert|8|kn|km/h}} to allow them to operate effectively around the entire British coast.,<ref>Douglas Botting, pp. 18–19 "The U-Boats", {{ISBN|978-0-7054-0630-7}}</ref> By contrast, the Royal Navy had a total of 74 submarines, though of mixed effectiveness. In August 1914, a flotilla of ten U-boats sailed from their base in [[Heligoland]] to attack Royal Navy warships in the [[North Sea]] in the first submarine war patrol in history.<ref>Gibson and Prendergast, p. 2</ref>

The U-boats' ability to function as practical war machines relied on new tactics, their numbers, and submarine technologies such as combination diesel–electric power system developed in the preceding years. More submersibles than true submarines, U-boats operated primarily on the surface using regular engines, submerging occasionally to attack under battery power. They were roughly triangular in cross-section, with a distinct [[keel]] to control rolling while surfaced, and a distinct bow. During World War I more than 5,000 [[Allies of World War I|Allied]] ships were sunk by U-boats.<ref>Roger Chickering, Stig Förster, Bernd Greiner, German Historical Institute (Washington, D.C.) (2005). "''[https://books.google.com/books?id=evVPoSwqrG4C&pg=PA73 A world at total war: global conflict and the politics of destruction, 1937–1945]''". Cambridge University Press. {{ISBN|978-0-521-83432-2}}, p. 73</ref>

The British responded to the German developments in submarine technology with the creation of the [[British K-class submarine|K-class submarines]]. However, these submarines were notoriously dangerous to operate due to their various design flaws and poor maneuverability.<ref>{{cite web |title=1915-1926: K Class |url=http://rnsubs.co.uk/boats/subs/k-class.html |website=RN Subs |publisher=Barrow Submariners Association |access-date=24 February 2019}}</ref><ref>{{cite web |url=https://www.theguardian.com/commentisfree/2017/nov/04/k-class-submarines-disaster-navy-britain-hms-vigilant |title=From the K-class to the party boat, submarines have a history of disaster |newspaper=The Guardian |date=4 November 2017 |author=Ian Jack |access-date=13 January 2022}}</ref>

====World War II====
{{See also|List of submarines of World War II}}
[[File:I400 2.jpg|thumb|The [[Imperial Japanese Navy]]'s {{sclass|I-400|submarine|2}}, the largest submarine type of WWII]]
[[File:U-47.jpg|thumb|A model of [[Günther Prien]]'s {{GS|U-47|1938|2}}, German WWII [[Type VII submarine|Type VII]] diesel–electric hunter]]

During [[World War II]], Germany used submarines to devastating effect in the [[Battle of the Atlantic]], where it attempted to cut Britain's supply routes by sinking more [[merchant ship]]s than Britain could replace. These merchant ships were vital to supply Britain's population with food, industry with raw material, and armed forces with fuel and armaments. Although the U-boats had been updated in the interwar years, the major innovation was improved communications, encrypted using the [[Enigma machine|Enigma cipher machine]]. This allowed for mass-attack [[naval tactics]] (''Rudeltaktik'', commonly known as "[[Wolfpack (naval tactic)|wolfpack]]"), which ultimately ceased to be effective when [[Cryptanalysis of the Enigma|the U-boat's Enigma was cracked]]. By the end of the war, almost 3,000 [[Allies of World War II|Allied]] ships (175 warships, 2,825 merchantmen) had been sunk by U-boats.<ref>{{cite book|last=Crocker III|first=H. W.|title=Don't Tread on Me|publisher=Crown Forum|year=2006|location=New York|page=[https://archive.org/details/donttreadonme40000croc/page/310 310]|isbn=978-1-4000-5363-6|url=https://archive.org/details/donttreadonme40000croc/page/310}}</ref><!--not solely by torpedo, I wager...--> Although successful early in the war, Germany's U-boat fleet suffered heavy casualties, losing 793 U-boats and about 28,000 submariners out of 41,000, a casualty rate of about 70%.<ref>{{cite news |title=The Battle of the Atlantic: The U-boat peril |url=https://www.bbc.co.uk/history/worldwars/wwtwo/battle_atlantic_01.shtml |work=BBC |date=30 March 2011}}</ref>

The [[Imperial Japanese Navy]] operated the most varied fleet of submarines of any navy, including ''[[Kaiten]]'' crewed torpedoes, midget submarines ({{sclass2|Type A Ko-hyoteki|submarine|5}} and {{sclass|Kairyu|submarine|4}}es), medium-range submarines, purpose-built supply submarines and long-range [[fleet submarine]]s. They also had submarines with the highest submerged speeds during World War II ({{sclass|I-201|submarine|2}}s) and submarines that could carry multiple aircraft ({{sclass|I-400|submarine|2}}s). They were also equipped with one of the most advanced torpedoes of the conflict, the oxygen-propelled [[Type 95 torpedo|Type 95]]. Nevertheless, despite their technical prowess, Japan chose to use its submarines for fleet warfare, and consequently were relatively unsuccessful, as warships were fast, maneuverable and well-defended compared to merchant ships.

The submarine force was the most effective anti-ship weapon in the American arsenal. Submarines, though only about 2 percent of the U.S. Navy, destroyed over 30 percent of the Japanese Navy, including 8 aircraft carriers, 1 battleship and 11 cruisers. US submarines also destroyed over 60 percent of the Japanese merchant fleet, crippling Japan's ability to supply its military forces and industrial war effort. [[Allied submarines in the Pacific War]] destroyed more Japanese shipping<!--because "shipping" means "merchant", generally, & that's the important factor--> than all other weapons combined. This feat was considerably aided by the Imperial Japanese Navy's failure to provide adequate escort forces for the nation's merchant fleet.

During World War II, 314&nbsp;submarines served in the US Navy, of which nearly 260 were deployed to the Pacific.<ref name="O'Kane, p. 333">O'Kane, p. 333</ref> When the Japanese attacked Hawaii in December 1941, 111 boats were in commission; 203 submarines from the {{sclass|Gato|submarine|5}}, {{sclass|Balao|submarine|5}}, and {{sclass|Tench|submarine|4}}es were commissioned during the war. During the war, 52 US submarines were lost to all causes, with 48 directly due to hostilities.<ref>Blair, Clay, Jr. ''Silent Victory'', pp. 991–92. The others were lost to accidents or, in the case of {{USS|Seawolf|SS-197|2}}, [[friendly fire]].</ref> US submarines sank 1,560&nbsp;enemy vessels,<ref name="O'Kane, p. 333" /> a total tonnage of 5.3&nbsp;million tons (55% of the total sunk).<ref name="Blair, p. 878">Blair, p. 878</ref>

The [[Royal Navy Submarine Service]] was used primarily in the classic Axis [[blockade]]. Its major operating areas were around Norway, in the [[Mediterranean]] (against the Axis supply routes to North Africa), and in the Far East. In that war, British submarines sank 2 million tons of enemy shipping and 57 major warships, the latter including 35 submarines. Among these is the only documented instance of a submarine sinking another submarine while both were submerged. This occurred when {{HMS|Venturer|P68|6}} [[Action of 9 February 1945|engaged]] {{GS|U-864||2}}; the ''Venturer'' crew manually computed a successful firing solution against a three-dimensionally maneuvering target using techniques which became the basis of modern torpedo computer targeting systems. Seventy-four British submarines were lost,<ref>{{cite web |url=http://www.royalnavy.mod.uk/server/show/nav.2558 |title=Submarine History |publisher=The Royal Navy |access-date=18 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070220150129/http://www.royalnavy.mod.uk/server/show/nav.2558 |archive-date=20 February 2007}}</ref> <!--something more than speculation on cause is wanted-->the majority, forty-two, in the Mediterranean.

====Cold-War military models====
[[File:HMAS Rankin at periscope depth.jpg|thumb|{{HMAS|Rankin|SSG 78|6}}, a {{sclass|Collins|submarine|2}} at periscope depth]]
[[File:USS Charlotte (SSN 766) steams in a close formation at RIMPAC 2014.jpg|thumb|upright|{{USS|Charlotte|SSN-766|6}}, a {{sclass|Los Angeles|submarine|2}} runs with submarines from partner nations during [[Exercise RIMPAC|RIMPAC]] 2014.]]

The first launch of a [[cruise missile]] ([[SSM-N-8 Regulus]]) from a submarine occurred in July 1953, from the deck of {{USS|Tunny|SSG-282|6}}, a World War II fleet boat modified to carry the missile with a [[nuclear weapon|nuclear warhead]]. ''Tunny'' and its sister boat, {{USS|Barbero|SSG-317|2}}, were the United States' first nuclear deterrent patrol submarines. In the 1950s, [[Nuclear marine propulsion|nuclear power]] partially replaced diesel–electric propulsion. Equipment was also developed to extract [[oxygen]] from sea water. These two innovations gave submarines the ability to remain submerged for weeks or months.<ref>{{cite web |url=https://ussnautilus.org/history-of-uss-nautilus/ |title=History of USS Nautilus (SSN 571)|publisher=[[Submarine Force Library and Museum|Submarine Force Museum]]|year=2006|access-date=16 January 2012}}</ref><ref>{{cite magazine|author=Tony Long|url=https://www.wired.com/science/discoveries/news/2007/05/dayintech_0510|title=10 May 1960: USS ''Triton'' Completes First Submerged Circumnavigation|magazine=Wired|date=10 May 2007|access-date=18 April 2010}}</ref> Most of the naval submarines built since that time in the US, the Soviet Union (now Russia), the UK, and France have been powered by a [[nuclear reactor]].

In 1959–1960, the first [[ballistic missile submarine]]s were put into service by both the United States ({{sclass|George Washington|submarine|4}}) and the Soviet Union ({{sclass2|Golf|submarine|4}}) as part of the [[Cold War]] [[nuclear deterrent]] strategy.

During the Cold War, the US and the Soviet Union maintained large submarine fleets that engaged in cat-and-mouse games. The Soviet Union lost at least four submarines during this period: {{ship|Soviet submarine|K-129|1960|2}} was lost in 1968 (a part of which the [[CIA]] retrieved from the ocean floor with the [[Howard Hughes]]-designed ship [[Hughes Glomar Explorer|''Glomar Explorer'']]), {{ship|Soviet submarine|K-8||2}} in 1970, {{ship|Soviet submarine|K-219||2}} in 1986, and {{ship|Soviet submarine|Komsomolets||2}} in 1989 (which held a depth record among military submarines—{{convert|1000|m|ft|abbr=on}}). Many other Soviet subs, such as {{ship|Soviet submarine|K-19||2}} (the first Soviet nuclear submarine, and the first Soviet sub to reach the North Pole) were badly damaged by fire or radiation leaks. The US lost two nuclear submarines during this time: {{USS|Thresher|SSN-593|6}} due to equipment failure during a test dive while at its operational limit, and {{USS|Scorpion|SSN-589|6}} due to unknown causes.

During the [[Indo-Pakistani War of 1971]], the [[Pakistan Navy]]'s {{ship|PNS|Hangor|S131|2}} sank the Indian frigate {{INS|Khukri|1958|6}}. This was the first sinking by a submarine since World War II.{{citation needed|date=December 2022}} During the same war, {{ship|PNS|Ghazi||2}}, a ''Tench''-class submarine on loan to Pakistan from the US, was sunk by the [[Indian Navy]]. It was the first submarine combat loss since World War II.<ref name="BR">{{cite web|url=http://www.bharat-rakshak.com/MONITOR/ISSUE4-2/harry.html |title=The Sinking of the Ghazi |work=Bharat Rakshak Monitor, 4(2) |access-date=20 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20111128104709/http://www.bharat-rakshak.com/MONITOR/ISSUE4-2/harry.html |archive-date=28 November 2011 }}</ref> In 1982 during the [[Falklands War]], the Argentine cruiser {{ship|ARA|General Belgrano||2}} was sunk by the British submarine {{HMS|Conqueror|S48|6}}, the first sinking by a nuclear-powered submarine in war.<ref>{{Cite book|title=Sink the Belgrano|last=Rossiter|first=Mike|publisher=Random House|year=2009|isbn=978-1-4070-3411-9|location=London|pages=305–18, 367–77|oclc=1004977305}}</ref> Some weeks later, on 16 June, during the [[1982 Lebanon War|Lebanon War]], an unnamed [[Gal-class submarine|Israeli submarine]] torpedoed and sank the Lebanese coaster ''Transit'',<ref name=":0">{{Cite web|last=|first=|date=|title=Stichting Maritiem Historische Data - Schip|url=https://www.marhisdata.nl/schip&id=2654|access-date=11 February 2021|website=www.marhisdata.nl|language=dutch}}</ref> which was carrying 56 Palestinian refugees to [[Cyprus]], in the belief that the vessel was evacuating anti-Israeli militias. The ship was hit by two torpedoes, managed to run aground but eventually sank. There were 25 dead, including her captain. The [[Israeli Navy]] disclosed the incident in November 2018.<ref>{{Cite web|last=|first=|date=22 November 2018|title=Israel admits it sank Lebanese refugee boat in 1982 war error, killing 25 — TV|url=https://www.timesofisrael.com/israel-admits-it-sank-lebanese-refugee-boat-in-1982-war-error-killing-25-tv/|access-date=11 February 2021|website=www.timesofisrael.com|language=en-US}}</ref><ref name=":0" />