NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brian Walton
Date: 2015 Sep 8, 07:17 -0700
You don't really need Polaris tables. Or a watch.
"Polaris goes to Queen Cassiopeia for tea." Polaris lies 40 miles or minutes towards the W of Cassiopeia from the true N Pole. A line from the bowl of the Dipper/Plough to the top right star of the W, goes through the N Pole. If the Dipper and /or the W are horizontal with Polaris, there is no correction. If the Dipper is vertically above Polaris, add 40' to the sextant. If the W is vertically above Polaris, take 40' away etc.
In between, is in between. It's like sines,15,30,45,60,75 degrees, go 40' x .3/.5/.7/.79/all. Just eyeball it. Draw a circle on graph paper if you really have to.
All you need now are refraction for Ho (latitude) and height of eye corrections.
Refraction; you probably won't see Polaris below N 5 d at sea. Hs 5 is -10', 10 is -5', and it's a straight line to 50 where it's 0 and on up.
Height of eye is - square root of height in feet.
Brian Walton
