A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Fred Hebard
Date: 2003 Mar 16, 20:45 -0500
The location of my house seems to be settling down to perhaps 0.3 to 0.4 nautical miles north of its actual location. All of this with an artificial horizon. One new technique I tried was to preset the sextant to the future altitude of a body and then watch the body pass through that altitude while listening to the time being counted out. My general objective is to get these observations as accurate as possible, say to within 0.1 or 0.2 miles. I'm not sure why I have this objective, but it persists. Bill Murdoch mentioned he had never bothered to apply instrument corrections to readings taken with his Freiberger, implying that it's not necessary to achieve accuracies better than about 1 nautical mile. That also seems to be the general opinion here, especially with regard to observations from small yachts, where it often is not possible to get more accurate. But how about larger vessels? Does anybody want to defend trying to get accuracies closer than 1 mile?