NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: A Complete Navigation Log: Thoughts on What Might Be Included
From: Tmstock
Date: 2009 Feb 04, 09:18 -0600
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From: Tmstock
Date: 2009 Feb 04, 09:18 -0600
Good points all - thanks. I have not done any serious CELNAV since the early '90s, and that was largely just the usually delivery crew standard of a few running fixes during the day and a set of stars and maybe Venus when I really needed a fix before a landfall. Lunars will be a new task, but should be manageable within the time frame. It's actually good to see ON reward the diligent...while most navigators bring a sextant racing these days, it's more likely to satisfy the race committee or a skipper with too much experience with marine electronics than for serious work.
Norville also covers a day's work in his 'Step-By-Step' (I learned from Mixter and Norville), but I'll take your advice and look for an older edition of Dutton.
Any opinion on whether tables, direct calculation, or a mix would be preferred? Seems like 249 or 229 give earlier indication of problems, but direct calc is much faster for me (engineer by training and trade). Work by table or calculator, then checking against Starpath for sanity and then GPS?
On Tue, Feb 3, 2009 at 3:45 PM, bmorris@tactronics.com wrote:
>
Hi
In my humble opinion, there is a quintesential approach that will "win points".
Get yourself a pre-1975 copy of Dunlap's "Navigation and Piloting". Pre-1975 since it predates GPS. Dunlap was used (may still be) at the US Naval Academy. Look at the section describing a day's work for the navigator. Follow it, to the letter.
The section describes exactly what would be required of a US Naval vessel in pre-GPS days. It will include such tidbits as the pre-calculation of observable bodies for the morning and afternoon twilights, remember to include the navigable planets. Use your 2102-D. Other tidbits will be swinging the compass to determine deviation via azimuth and or amplitude sights. Another would be preparation for LAN and the LOP associated with it. There is much to learn!
Dunlap is readily available on eBay, usually for less than $20 including shipping.
One other approach is to look at Bowditch, 1800's. He describes how to maintain a navigational logbook. This approach would include lunars and etc. Certainly, that will differentiate you, however be careful to practice before you use it. As you can see from many listings in the NavList, there is a sensitivity in measurement. Getting it "wrong" may actually detract from your log.
Anyway, that's just one person's opinion. And like belly buttons, we all have one!
Good Luck in your endeavors.
Best Regards
Brad
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