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    Re: Bowditch Table 15
    From: Bill B
    Date: 2005 Jan 26, 16:25 -0500

    In my 1995 version, it is article 2203, and actually gives the correct
    formula for table 15 (two terms under the radical symbol)!  I do not think a
    chunk of text is missing, as the Explanation of  Navigation Tables uses a
    parallel format.
    > I searched through the rest of Bowditch 2002 for more references to the
    > Table 15 procedure, and found this odd paraphraph in Chapter 22, Article
    > 2202:
    > "Distance by vertical angle between the waterline and the top of an object
    > is computed by solving the right triangle formed between the observer, the
    > top of the object, and the waterline of the object by simple trigonometry.
    > This assumes that the observer is at sea level, the Earth is flat between
    > observer and object, there is no refraction, and the object and its
    > waterline form a right angle. For most cases of practical significance,
    > these assumptions produce no large errors.
    > D = sqrt[(tan^2a/.0002419^2) + ((H-h)/0.7349)] - (tan a/.002419)
    > where D is the distance in nautical miles, a is the corrected vertical
    > angle, H is the height of the top of the object above sea level, and h is
    > the observer's height of eye in feet. The constants (0.0002419 and 0.7349)
    > account for refraction.".
    > I don't see why the Table 15 equation is given in this paragraph.  Looks to
    > me like a chunk of text is missing between the end of "...produce no large
    > errors" and the equation, and that in fact the second half, which contains
    > the equation, belongs to a missing title that should describe "Distance by
    > Vertical Angle Measured Between Sea Horizon and Top of Object Beyond Sea
    > Horizon".  Can someone check an older Bowditch?

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