A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ed Popko
Date: 2016 Feb 2, 05:59 -0800
Now here is an interesting navigation slide rule - and 3D too... The Astra-Plot a "three dimensional slide-rule" for celestial navigation, 1969
According to the writeup:
Five specific data to specify the location of a ship
The device specifies the location of a ship to within one nautical mile without the need of any paper calculations. Five specific data are required: First, the approximate position of the ship as determined by the compass bearing and travel time; second, the height of a star above the horizon, preferably the sun, as measured by a sextant; third, the exact compass direction of that star as determined by an amplitude compass; fourth, its hour angle as determined by the time of day and a nautical chart and, fifth, the angular distance of the star to the celestial equator as determined by the nautical chart or the star map.