NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Fwd: Principles and Being Practical
From: Peter Fogg
Date: 2003 Sep 7, 13:15 +1000
From: Peter Fogg
Date: 2003 Sep 7, 13:15 +1000
> From: George Huxtable > The problem with these azimuth tables ... > is not in their ambiguity, but in their inaccuracy, and that > inaccuracy is > exactly what I have complained about. And there is not one word, not > even a > hint, in the book that major errors in azimuth can occur, for certain > observations in a VERY wide swathe around East or West. Inserted in second edition is . "In extreme cases the table should be interpolated when observations have been made in the vicinity of the prime vertical and/or LHA, declination and latitude require substantial rounding off before using the table. When in doubt use the Weir diagrams. In practice you could happily sail across an ocean and never notice this supposed problem, particularly by following the common sense approach outlined previously. With nav. it it often a case of one system checking another. In fact taking sights and working out a fix is a check on the basic tool of running a DR. If the whole book has been subjected to the same searching criticism and this rather inconsequential nit-pick is the only flaw found, then it is really a back-handed compliment to the book as a whole. A ferocious critic seems to think the rest works just fine.