NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2016 Dec 30, 11:25 -0800
The UPS has the same Latitude scale ( NM per inch ) at 10 degrees north and at 50 degrees north. A Mercator chart does not.
John H.
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That's true, if you want to make a chart that covers the entire range from 10 to 50 degrees, but if you just want to make a small area plotting sheet covering 10 to 11 degrees or 49 to 50 degrees then each of those separate small area plotting sheets will have constant scales.
gl
Gary,
If you sail from Cancun to New Orleans ( basicly North ) and use a UPS every day for say 2 degrees then when you get to New Orleans you can tape all of your UPSs end on end and see your trip ( voyge )
That is what I was getting at - a scale of 20 miles per inch will be good for the whole trip. On a Mecator chart ( as you know ) the last 100 miles would look longer than the first 100 miles. On a UPS both would look the same.
John H.
