Submarine navigation

Submarine navigation underwater requires special skills and technologies not needed by surface ships. The challenges of underwater navigation have become more important as submarines’ spend more time underwater, travelling greater distances and at higher speed. Military submarines travel underwater in an environment of total darkness with neither windows nor lights. Operating in stealth mode, they cannot use their active sonar systems to ping ahead for underwater hazards such as undersea mountains, drilling rigs or other submarines. Surfacing to obtain navigational fixes is precluded by pervasive anti-submarine warfare detection systems such as radar and satellite surveillance. Antenna masts and antenna-eqipped periscopes can be raised to obtain navigational signals but in areas of heavy surveillance, only for a few seconds or minutes; [cite book | last = Bivens | first = Arthur Clarke | title = From Sailboats to Submarines | year = 2004 | month = July | publisher = Infinity Publishing | isbn = 978-0741421524 | pages = 184 ] current radar technology can detect even a slender periscope while submarine shadows may be plainly visible from the air.

Surfaced submarines entering and leaving port navigate similarly to traditional ships but with a few extra considerations because most of the ship rides below the waterline, making them hard for other ships to see and identify.

Navigational technologies

urface and near-surface navigation

On the surface or at periscope depth, submarines have used these methods to fix their position:
*Satellite navigation:
**Global positioning system (GPS)
**NAVSAT
*Terrestrial radio-based navigation systems; largely superseded by satellite systems
**LORAN
**CHAYKA, the Russian counterpart of LORAN
**OMEGA, the Western counterpart of the Alpha Navigation System, no longer in use
**Alpha, the Russian counterpart of the Omega Navigation System
*Celestial navigation using the periscope -- seldom used anymore
*Radar navigation; radar signals are easily detected so radars is normally only used in friendly waters entering and exiting ports.
*Active sonar; like radar, active sonar systems are readily detected, so active sonar is usually used only entering and exiting ports.
*Pilotage -- in coastal and internal waters, surfaced submarines rely the standard system of navigational aids (buoys, navigational markers, lighthouses, etc.)

Deep water navigation

At depths below periscope depth submarines determine their position using:
*Dead reckoning#Marine Navigation course information obtained from the ship's gyrocompass, measured speed and estimates of local ocean currents.
*Inertial navigation system
*Bottom contour navigation may be used in areas where detailed hydrographic data has been charted and there is adequate variation in sea floor topography. [ cite web|url = http://www2.ku.edu/~kunrotc/academics/300/Lesson14%20Electronic%20Navigation.ppt |title = Lesson 14: Electronic Navigation |accessdate = 2007-11-14 |format = Microsoft PowerPoint |work = Navigation and Operations I |publisher = University of Kansas, Naval Reserve Officer Training Corps |pages = Slides 19 to 21] [cite web
url = https://www.navigator.navy.mil/navigator/ECDIS/Policy_Standards/CJCSI_6130_01C_MasterPNT.pdf |title = 2003 CJCS Master Positioning, Navigation, And Timing Plan |accessdate = 2007-11-14 |format = PDF |publisher = Joint Chiefs of Staff |pages = page F-12] [cite news | first = Hamn | last = S. E.| title = Coastal piloting: bottom contour navigation.(Seamanship) | url = http://findarticles.com/p/articles/mi_hb5263/is_199508/ai_n20411943| publisher = Trailer Boats | date = August 1995 | accessdate = 2007-11-14] Fathometer depth measurements are compared to charted depth patterns.

ee also

*Bearing (navigation)
*Sonar#Passive sonar

Footnotes

References

*cite book | last = Clancy | first = Tom | authorlink = Tom Clancy | coauthors = John Gresham | title = Submarine: A Guided Tour Inside a Nuclear Warship | origdate = | origyear = 1993 | edition = Revised edition | date = 2002-01-08 | publisher = Berkley Books | location = | isbn = 978-0425183007
*cite book | last = Craven | first = John Piña | authorlink = John Piña Craven | title = The Silent War: The Cold War Battle Beneath the Sea | origdate = 2001-03-15 | publisher = Simon & Schuster | location = New York, New York | isbn = 978-0684872131
*cite book | last = DiMercurio | first = Michael | coauthors = Michael Benson | title = Complete Idiot's Guide to Submarines | origdate = 2003-02-04 | publisher = Alpha Books | location = Indianapolis, Indiana | isbn = 978-0028644714
*cite book | last = Harris | first = Brayton | title = Navy Times Book of Submarines | origdate = 1997-12-01 | edition = First edition | publisher = Berkley Hardcover | location = New York, New York | isbn = 978-0425157770
*cite book | last = Hutchinson | first = Robert | title = Jane's Submarines: War Beneath the Waves from 1776 to the Present Day | origdate = 2005-11-01 | publisher = HarperCollins Publishers | location = | isbn = 978-0060819002
*cite book | last = Leary | first = William M. | title = Under Ice: Waldo Lyon and the Development of the Arctic Submarine | origyear = 1999 | origmonth = January | edition = First edition | publisher = Texas A&M University Press | location = College Station, Texas | isbn = 978-0890968451
*cite book | last = Miller | first = David | title = Modern Submarine Warefare | origdate = 1988-12-12 | edition = First edition | publisher = Crescent | isbn = 978-0517646472
*cite book | last = Parrish | first = Tom | title = The Submarine: A History | origdate = 2004-05-06 | publisher = Viking Penguin | location = New York, New York | language = | isbn = 978-0670033133
*cite book | last = Preston | first = Antony | authorlink = Antony Preston (naval historian) | title = Submarine Warfare: An Illustrated History | origdate = | origyear = 1999 | origmonth = April | publisher = Thunder Bay Press | location = San Diego, California | isbn = 978-1571451729
*cite book | last = van der Vat | first = Dan | authorlink = Dan van der Vat | title = Stealth at Sea: The History of the Submarine | origdate = 1995-04-03 | publisher = Houghton Mifflin | location = | isbn = 978-0395652428
*cite book | last = Waller | first = Douglas C. | authorlink = Douglas C. Waller | title = Big Red: Three Months on Board a Trident Nuclear Submarine | origdate = 2001-03-06 | publisher = HarperCollins Publishers | location = | isbn = 978-0060194840