Re: Bowditch editions: good and bad
From: James F Campbell
Date: 2021 Feb 19, 15:36 -0800
[moved from reply to another thread]
I have assembled the pieces and parts of a letter to be drafted to the NGA re Chapter 3 in volume 2 of the 2019 ed. NGA copied the Appendix Q from the 1977 and 1984 editions inserted it into the 2017/2017 eds. as Chapter 3.Parts are missing, paragraphs were dropped, important graphics have been left out, and some very cirtical formulae have been slaughtered. For example, one formula has you using the SIN of a 'distance' that is denominated in Nautical Miles!
I feel somewhat that I am partly to blame. I contacted NGA in 2015 re getting a good copy of Appendix Q to reproduce to share with some professional colleagues. I actually got a telephone call from someone at NGA apologizing for omitting all the Math from the 1998, and 2002 editons of Bowditch. I was directed to the subject Appendix Q by a footnote in Chapter 16 of the Admiralty Manual of Navigation. Then in the 2017 edition the subject Chaptere 3 appears.
My interest has to do with Maritime Search and Rescue Planning. Particularily, determining the semi-major and semi-minor axes of the 95% ellipse of containment. Turns out that it is easy using Excel, but exceedingly tedious for the Manual Method that is contained in the ICAO/IMO IAMSAR Manual.
James F. Campbell
North Chesterfield, VA