NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Hanno Ix
Date: 2014 Jun 30, 11:01 -0700
Bygrave, at least than my B-size flat Bygrave with R. Stuart's excellent scales.
And for Doniol I do not use any calculator, do all the work be hand. In your list
you did not mention that single multiplication. For that I prefer Vedic since it
( Chichester ) but for the hobby navigator or for a Blue Water CelNav certificate / application Doniol seems hard to beat.
Doniol longhand sight reduction summary.
Pros:
1. Simple rules.
2. Easy to memorize.
3. Uses DR as assumed position.
4. Fast four place precision.
5. Flexible for longhand, log, slide rule, or basic non trig calculator.
6. Works with as few as 2 pages of cosine sine tables.*
7. Reduction fits on one side of an index card with room to spare.
8. No form needed.
Cons:
1. A few subtraction steps.
2. Azimuth is not reduced. **
* A 6 page haversine table is recommended to save time and reduce errors.
** The classic azimuth formula using diagram , slide rule, or longhand to 2 places complements the Doniol Hc formula.
The pros far out weigh the cons making Doniol a leading contender to replace the clumsy NASR at the back of the Nautical Almanac.
Greg Rudzinski
http://fer3.com/arc/m2.aspx/Longhand-Sight-Reduction-Rudzinski-jun-2014-g27966
