Wallet Trig Log Scale for Navigation Calculations

A photo copy of a slide rule trig log scale will make for a very nice sextant box and wallet navigation calculator using a pair of chart dividers. The principle is the same as using a slide rule and good enough for most navigation calculations. Give a try for time,speed, distance, plotting sheet scaling, azimuth, amplitude, prime vertical. Even more advanced calculations of ex-meridian and circle of position radius can be done to sufficient precision.

Use this virtual slide rule link to select prefered slide rule to screen capture for printing. https://www.sliderules.org/