A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2015 Dec 24, 17:31 -0500
I've always regarded the 2102D as an exceptional complement to the Nautical Almanac. The same 57 navigational stars are present in both.
It helps to set up a round of sights by allowing you compute the sextant present without much fuss at all. Pick 4-6 stars, precompute, and then, in the 20-30 minutes available at twilight, use the best three for a good distribution of LOPs.
It's not terrifically accurate, but then again, it doesn't need to be. What's not to like?
Not every individual who pulls out a sextant is going to be the extraordinary master of the details of the stars in the sky. Frankly, who needs to be?
The U.S. Navy 2102-D is better than the commercial editions I think. The template pin is brass not nylon. The disc is still white after half a century and the templates have remained clear. This example was made after 1956 and originally priced at $4. I was happy to pay $20 for this one in very good condition.
From: Greg Rudzinski
Date: 2015 Dec 19, 10:38 -0800
The latest mods for my 2102-D has one version as a disc which fits in the 2102-D pouch. The other is a folder. Each are marked to set the disc north side up to day of the month of Aries (clockwise at 30° per month 1° per day) and the latitude template to zone time (counterclockwise at 15° per hour). On the left of the folder are good enough values for declination and merdian passage for plotting the Sun's LAN altitude on the disc with the template set to the time of meridian passage. I find this easier than using the red template and saves wear and tear on the various template holes from repeated detachments.
There is no need to be precise with this star finding tool for it's intended purpose. It is more than good enough for sight planning, star I.D., and civil twilight presets. If better presets are needed then go to Pub 249 vol. 1 selected stars (any epoch will work).
(2102-D-Aries-LTA-Disc.jpg: Open and save)
(2102-D-Aries-LTA-Folder.jpg: Open and save)
(Navy-Star-Finder.jpg: Open and save)
(Navy-Star-Finder-2.jpg: Open and save)
(Navy-Star-Finder-Pin.jpg: Open and save)
(Navy-Star-Finder-Instructions_.jpg: Open and save)
(Navy-Star-Finder-Instructions-1.jpg: Open and save)