Lu wrote:
"Would I want the bulk of Bygrave slide rules or would a calculator suffice?"
------------------------------------------
The "bulk" of the flat Bygrave is 0.033 inches and the "bulk" of the
long term almanac, which consists of only four pages sealed inside of
plastic sheets, total an additional 0.044 inches. The complete flat
Bygrave celestial navigation kit is only 0.077 inches thick on a
bookshelf, weighing only 4.6 ounces. The Nautical Almanac, with the NAO
sight reduction table, is 0.937 inches thick and weighs 26.5 ounces. The
NA takes up twelve times more shelf space and weighs six times as much!
And if you carry H.O. 229, well see:
http://fer3.com/arc/m2.aspx/New-compact-backup-CELNAV-system-RENAMED-Accuracy-Bygrave-Slide-LaPook-oct-2010-g14077
The attached photo shows the entire kit.
gl
--- On Thu, 4/4/13, Lu Abel <luabel@ymail.com> wrote:
From: Lu Abel <luabel@ymail.com>
Subject: [NavList] Re: Which Method do you prefer using and why.
To: garylapook@pacbell.net
Date: Thursday, April 4, 2013, 2:30 PM
If I were to go offshore in a private boat (ie, not a 1000' ship) how
much space and weight (and money) is it practical to devote to
navigational gear? Would I want to carry four heavy, bulky volumes of
HO229? If so, why? Would I want the bulk of Bygrave slide rules or would a calculator suffice? Why? Etc, etc, etc. Lu
--- On Thu, 4/4/13, Lu Abel <luabel@ymail.com> wrote:
From: Lu Abel <luabel@ymail.com>
Subject: [NavList] Re: Which Method do you prefer using and why.
To: garylapook@pacbell.net
Date: Thursday, April 4, 2013, 2:30 PM
Stan, you've inspired some clarity for me. It seems to me there are a variety of people who are on this list: 1. People who want to learn celestial. A goodly
subset of them are probably "want to learn celestial as a backup to GPS for offshore voyaging." 2. People who want to learn (or learn about) historical techniques -- everything from lunars to how Captain Cook might have navigated. 3. People who don't trust anything with electronics inside it. What sometimes bothers me is when people don't make it clear what camp they belong to (or maybe they're not even in touch). Having cut my celestial teeth on HO229, I can't put myself in the camp that says it's faster than Law of Cosines on a calculator. But my major point is to hope that if people
want to talk about celestial navigation in the 21st century they will be practical about it. If I were to go offshore in a private boat (ie, not a 1000' ship) how much space and weight (and money) is it practical to devote to navigational gear? Would I want to carry four heavy, bulky volumes of HO229? If so, why? Would I want the bulk of Bygrave slide rules or would a calculator suffice? Why? Etc, etc, etc. Maybe because I am a US Power Squadrons member and have taught their celestial courses, I agree with their view of offshore navigation for the 21st century -- (1) celestial is a backup to GPS, and (2) the Nautical Almanac sight reduction tables are a good backup to LOC/calculator reductions because they're in the NA and therefore you don't have to carry anything extra. Lu
From: Stan K <slk1000---com>
To: luabel---com
Sent: Thursday, April 4, 2013 1:45 PM
Subject: [NavList] Re: Which Method do you prefer using and why.
Geoffrey,
The NAO tables are one of the only two methods currently taught by the United States Power Squadrons (USPS), the other being the Law of Cosines "calculator" method.
The Power Squadrons has been trying to make their courses more practical, admitting that GPS has replaced celestial as the primary offshore positioning method. However, they still support celestial as a backup and as a method of checking your GPS. With that in mind, they decided that NAO would be the only tabular method taught, since it is contained in the one book you are required to have anyway, the Nautical Almanac.
This makes some sense, until you consider why people take the two courses that still included celestial navigation, Junior Navigator and Navigator. Informal surveys have shown that only 10% of those taking the courses ever expect to use what they learned offshore (and only a small percentage of those actually do). People take thes courses because they are interested in the material. They want to understand what was cone in the historical novel they just read. They want to learn about the things that they use every day and never give a second thought. An example I use in class is the times of sunrise and sunset announced on the radio - how much does it matter exactly where you are?
Several of us involved in the USPS courses would like to see some of what has been removed from the courses (e.g. there is no mention of the Equation of Time) put back, but we may be fighting a losing battle. One thing being considered is putting the removed material into a supplemental program. Time will tell.
Stan
-----Original Message-----
From: Geoffrey Kolbe <geoffreykolbe---com>
To: slk1000 <slk1000---com>
Sent: Thu, Apr 4, 2013 1:04 am
Subject: [NavList] Re: Which Method do you prefer using and why.
Is there anybody out there, anybody at all, who uses the NAO tables in the back of the Nautical Almanac (and also in the back of the 2nd edition of my LTA)
Geoffrey Kolbe
View and reply to this message: http://fer3.com/arc/m2.aspx?i=123333 View and reply to this message: http://fer3.com/arc/m2.aspx?i=123334
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