NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Bowditch 1995 Table 18
From: Bill B
Date: 2005 Feb 2, 01:24 -0500
From: Bill B
Date: 2005 Feb 2, 01:24 -0500
Moving forward with "editors that do not know the subject matter"--or maybe it is just me--I would like to look at table 18, "Distance of an Object by Two Bearings." My premises: Bearing is the direction (cardinal angle) between the observer's north and the object, true or magnetic. That being clockwise, 0 to 360 or 0 to 359.xxx. Relative bearing is the angle between the bow end of the lubberline and the object, clockwise, 0 to 359,xxxd (or 0 to 360d, depending on your religion ;-) Bearing on the Bow is the angle between the bow end of the lubberline and the object, clockwise or counterclockwise, from 0-180d. The 1995 Bowditch, "Explanation of Navigation Tables" states for table 18: "To determine the distance of an object as a vessel on a steady course passes it, observe the difference between the course and two bearings of the object....Enter the table with the two differences..." My example, by the book: Course 2d true, object and shoreline to port First bearing 295d true, difference 293 d Second bearing, 245d true, difference 243d Now I go to the table. Whoops! No values greater than 160d for entering arguments. I can understand that we want an reasonable difference in angles between two LOP's to obtain an useable running fix; but darn, here we have a system that only works on the starboard side of the boat! Q: Have I, as is most often the case, missed something? If not; A. How should the above sentences read? B. Given the errors already exposed in recent editions of "American Practical Navigator," how does the nautical community send a message to the editor/publisher that the lapses are unacceptable? Bill