Editing Fin (section)

==Motion control==
[[File:Orca porpoising.jpg|thumb|right|{{center|Fins are used by aquatic animals, such as this [[orca]], to generate thrust and control the subsequent motion.<ref>* {{cite journal | last1 = Fish | first1 = FE | year = 2002 | title = Balancing requirements for stability and maneuverability in cetaceans | journal = Integrative and Comparative Biology | volume = 42 | issue = 1| pages = 85–93 | doi = 10.1093/icb/42.1.85 | pmid=21708697| doi-access = free }}</ref><ref>* {{cite journal | last1 = Fish | first1 = FE | last2 = Lauder | first2 = GV | s2cid = 4983205 | year = 2006 | title = Passive and active flow control by swimming fishes and mammals | journal = Annual Review of Fluid Mechanics | volume = 38 | issue = 1| pages = 193–224 | doi = 10.1146/annurev.fluid.38.050304.092201 | bibcode = 2006AnRFM..38..193F }}</ref>}}]]

Once motion has been established, the motion itself can be controlled with the use of other fins.<ref name=Sfakiotakis /><ref name=Perez /><ref name=McClamroch /> Boats control direction (yaw) with fin-like rudders, and roll with stabilizer and keel fins.<ref name=Perez>Perez, Tristan (2005) [https://books.google.com/books?id=lxlO3d2srAIC ''Ship Motion Control: Course Keeping and Roll Stabilisation Using Rudder and Fins''] {{Webarchive|url=https://web.archive.org/web/20231216095310/https://books.google.com/books?id=lxlO3d2srAIC |date=2023-12-16 }} Springer. {{ISBN|9781852339593}}.</ref> Airplanes achieve similar results with small specialised fins that change the shape of their wings and tail fins.<ref name=McClamroch>McClamroch, N Harris (2011) [https://books.google.com/books?id=DKK7m8o7_ZkC&pg=PA58 ''Steady Aircraft Flight and Performance''] {{Webarchive|url=https://web.archive.org/web/20231216095310/https://books.google.com/books?id=DKK7m8o7_ZkC&pg=PA58#v=onepage&q&f=false |date=2023-12-16 }}  Page 2–3, Princeton University Press. {{ISBN|9780691147192}}.</ref>

{{multiple image
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| header            = Specialised fins are used to control motion
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| image1            = Rotations.png
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| caption1          = Fish, boats and airplanes need control of three degrees of [[Degrees of freedom (mechanics)|rotational freedom]].<ref name=Magnuson>Magnuson JJ (1978) [https://books.google.com/books?id=wnjnyAafAzUC&pg=PA239 "Locomotion by scombrid fishes: Hydromechanics, morphology and behavior"] {{Webarchive|url=https://web.archive.org/web/20231216095310/https://books.google.com/books?hl=en&lr=&id=wnjnyAafAzUC&oi=fnd&pg=PA239#v=onepage&q&f=false |date=2023-12-16 }} in ''Fish Physiology'', Volume 7: Locomotion, WS Hoar and DJ Randall (Eds) Academic Press. Page 240–308. {{ISBN|9780123504074}}.</ref><ref>[http://www.pomorci.com/Zanimljivosti/Ship's%20movements%20at%20sea.pdf Ship's movements at sea]  {{webarchive|url=https://web.archive.org/web/20111125015923/http://www.pomorci.com/Zanimljivosti/Ship%27s%20movements%20at%20sea.pdf |archive-url=https://web.archive.org/web/20100821040522/http://www.pomorci.com/Zanimljivosti/Ship's%20movements%20at%20sea.pdf |archive-date=2010-08-21 |url-status=live |date=November 25, 2011 }} Retrieved 22 November 2012.</ref><ref>Rana and Joag (2001) [https://books.google.com/books?id=1kxkdWGa9-cC&pg=PA391 ''Classical Mechanics''] {{Webarchive|url=https://web.archive.org/web/20231216095310/https://books.google.com/books?id=1kxkdWGa9-cC&pg=PA391 |date=2023-12-16 }} Page 391, Tata McGraw-Hill Education. {{ISBN|9780074603154}}.</ref>
| image3            = White shark (cropped).jpg
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| caption3          = The dorsal fin of a white shark contain [[dermal]] fibers that work "like riggings that stabilize a ship's mast", and stiffen dynamically as the shark swims faster to control roll and yaw.<ref>{{cite journal | last1 = Lingham | last2 = Soliar | first2 = T | s2cid = 827610 | year = 2005 | title = Dorsal fin in the white shark, ''Carcharodon carcharias'': A dynamic stabilizer for fast swimming | journal = Journal of Morphology | volume = 263 | issue = 1| pages = 1–11 | doi = 10.1002/jmor.10207 | pmid=15536651}}</ref>
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[[File:Great white shark, Carcharodon carcharias.jpg|thumb|Caudal fin of a [[great white shark]]]]

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 | image1    = Yacht keel steer.svg
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 | caption1  = A [[rudder]] corrects yaw
 | image2    = 	Yacht keel.svg
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 | caption2  = A fin [[keel]] limits roll and sideways drift
 | image3    = Stabilizer1.JPG
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 | caption3  = Ship [[Stabilizer (ship)|stabilising fins]] reduce roll
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 | image1    = Aileron roll.gif
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 | caption1  = [[Aileron]]s control roll
 | image2    = Aileron pitch.gif
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 | caption2  = [[Elevator (aircraft)|Elevators]] control pitch
 | image3    = Aileron yaw.gif
 | width3     = 145
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 | caption3  = The [[Rudder#Aircraft rudders|rudder]] controls yaw
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Stabilising fins are used as [[fletching]] on [[arrow (weapon)|arrow]]s and some [[Dart (missile)|darts]],<ref>Vujic, Dragan (2007) [https://books.google.com/books?id=YsiPb2nmYdEC&pg=PA17 ''Bow Hunting Whitetails''] {{Webarchive|url=https://web.archive.org/web/20231216095311/https://books.google.com/books?id=YsiPb2nmYdEC&pg=PA17 |date=2023-12-16 }} Page 17, iUniverse. {{ISBN|9780595432073}}.</ref> and at the rear of some [[bomb]]s, [[missile]]s, [[rocket]]s and self-propelled [[torpedo]]es.<ref>Hobbs, Marvin (2010) [https://books.google.com/books?id=a0TxaTq2rQIC&pg=SA1-PA24 ''Basics of Missile Guidance and Space Techniques'']  Page 24, Wildside Press LLC. {{ISBN|9781434421258}}.</ref><ref>Compon-Hall, Richard (2004) [https://books.google.com/books?id=EEJ6YaMGkV4C&pg=PA50 ''Submarines at War 1939–1945''] {{Webarchive|url=https://web.archive.org/web/20231216095824/https://books.google.com/books?id=EEJ6YaMGkV4C&pg=PA50#v=onepage&q&f=false |date=2023-12-16 }}  Page 50, Periscope Publishing. {{ISBN|9781904381228}}.</ref>  These are typically [[Plane (geometry)|planar]] and shaped like small wings, although [[grid fin]]s are sometimes used.<ref>Khalid M, Sun Y and Xu H (1998) [ftp://ftp.rta.nato.int/Pubfulltext/RTO/MP/.../RTO-MP-005/$MP-005-12.pdf "Computation of Flows Past Grid Fin Missiles"]{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}} ''AVT Symposium on Missile Aerodynamics'', Sorrento, Italy.</ref> Static fins have also been used for one satellite, [[GOCE]].

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 | header            = Static tail fins are used as stabilizers
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 | image1    = Fletching-Arrow-9.jpeg
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 | caption1  = [[Fletching]] on an [[arrow]]
 | image2    = 122 mm raketti Hämeenlinna 2.JPG
 | width2     = 154
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 | caption2  = Asymmetric stabilizing fins impart spin to this Soviet artillery rocket 
 | image3    = USS Essex (LHD-2) launches RIM-7 Sea Sparrow on 6 February 2004 (040206-N-2970T-002).jpg
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 | caption3  = Conventional "planar" fins on a [[RIM-7 Sea Sparrow]] missile
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