NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Gnomonic Charts - Usable Zones
From: John D. Howard
Date: 2018 Jan 19, 08:38 -0800
From: John D. Howard
Date: 2018 Jan 19, 08:38 -0800
Bob,
Your question sums up one of the big problems of navigation. You cannot sail a great circle course! If you want to sail a great circle route than your course will change all the time ( unless going north-south or east-west )
Transverse tables are used to find Lat. and Long. after sailing a course for so many miles but they do so on a plane, not a sphere. When sailing a great circle route ( or flying, which I am more familiar with ) you sail short rhumbline course, then change course and sail another short segment then repeat. Line of sight sailing ( or flying ) is great circle but your course changes.
John H.
