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SextantNavigation

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= Navigating with a Sextant =
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In the event of an emergency when you lose your navigational electronics it would be useful to know how to navigate using a sextant. The simplest calculation is when you take a sun shot at local apparent noon (LAN).<ref>http://www.navigation-spreadsheets.com/noon_shots.html</ref> <ref>http://celestialnavigation.net/practice/</ref>
* Sextant
* Mechanical clock set to [https://en.wikipedia.org/wiki/Greenwich_Mean_Time Greenwich Mean Time] (GMT)
* Mechanical clock set to local timeSome means of determining noon
* Celestial [http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0013 Sight Reduction Tables for Marine Navigation] tables
== Sun Shot at Local Apparent Noon ==
 
Use the sextant to track the sun angle to determine its maximum zenith, which is local noon.
=== Latitude ===
=== Longitude ===
To determine longitudeusing a chronometer at local noon:<ref>https://en.wikipedia.org/wiki/Longitude_by_chronometer</ref>
* Note the precise time of noon GMT
* Know the local noon timeat this moment* If local noon is before GMT noon you asre are on eastern logitutde* If local noon is after GMT noon you asre are on western logitutde
Each difference of 4 minutes = 1 degree longitude
 
== Other Sightings ==
 
Other sightings of the sun (not at noon), moon or stars are complex and beyond the scope of this article. See also [[LearnToNavigate]].
== References ==
[[Category:NavigatingOperations]]