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GPS Backup with a Mark 3 Sextant
Background Article on our Modern Regiment of the North Star
Expanded Tables (to remove or minimize interpolation)
Practice with Dec and GHA
PRACTICE Finding sun's declination using the Backup Sun Almanac
Finding UTC of LAN
Finding UTC of LAN using the Starpath Custom Sun Almanac
Miscellaneous related articles
Accuracy of Back up Cel Nav Using a Mark 3
Progress to Weather ... a topic that comes up in some exercises that use this book
The book mentions putting together a backup kit made up of this book, a Mark 3 sextant, and a rated watch. We have such a kit availabe which includes all other aids needed to for ocean navigation. See contents at Starpath GPS backup kit.
PRACTICE with Latitude by Polaris
Example 1: With the sky below...
July 19, 2021, UTC = 05:56:28
DR: 44N, 141W
Hs Polaris = 43° 23.4'
IC=0
HE=10ft
What is your latitude? Solution 1Example 2: with the sky below...
July 14, 2020, UTC = 14:42:44
DR: 25N, 151W
Hs Polaris = 25° 29.4'
IC=0
HE=10ft
Find your latitude. Solution 2
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Errata
Page 35, Example 1, August 25 should be August 15.
Page 8, Step 3, first paragraph, discussing rocking the sextant, the axis should be "eyepiece-to-horizon-mirror" not index.