SextantNavigation

Revision as of 18:55, 15 October 2015 by DavidShaw (Talk | contribs) (Tools)

Revision as of 18:55, 15 October 2015 by DavidShaw (Talk | contribs) (Tools)

Navigating with a Sextant

In the event of an emergency when you lose your navigational electronics it would be useful to know how to navigate using a sextant.

Tools

  • Sextant
  • Mechanical clock set to GMT
  • Mechanical clock set to local time
  • Celestial tables

Latitude

To determine latitude:

  • Point the sextant at the horizon
  • Look through the tekescope
  • Adjust the index mirror with the index bar until the Sun aligns with the horizon
  • Read the angle from the arc
  • Note the exact time
  • Consult a celestial table to calculate the latitude

Longitude

To determine longitude:

  • Note the precise time of noon GMT
  • Know the local noon time
  • If local noon is before GMT noon you asre on eastern logitutde
  • If local noon is after GMT noon you asre on western logitutde

Each difference of 4 minutes = 1 degree longitude