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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...
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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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This book is now in the 7th printing. Earlier printings had several typos including these two
Errata
Page 4, Figure 2-2, Insert should look like:
Page 17. Table 5-2, Lat should be 35° 80,6' (36° 20,6'). Error source earlier in the table: Ho = 75° 14,0', not 74° 14,0'.