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From: Bill (no email)
Date: Wed Feb 02 2005 - 01:24:26 EST
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
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