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    Re: mid-longitude sailing
    From: Bill B
    Date: 2007 Jan 09, 21:26 -0500

    George wrote:
    > I haven't come across that method before. It seems a simple way to
    > split up a long ocean passage. It's exact, not an approximation, and
    > it does seem to give the right amswers. Can anyone see snags?
    Outstanding George, and simple. Thank you for an excellent contribution.
    Snags?  The obvious--cosine or tangent of 90d.  I imagine a bit sketchy in
    areas approaching 90d with a pocket calculator.  I did play with departure
    and destination latitudes approaching zero and those seem to be a wee bit
    off at first blush. I need to compare that to other methods of calculation
    before I can say for sure.   If there is a difference, I don't know how much
    is contributed by the use of a pocket calculator.  At any rate, I don't
    foresee that situation as a problem in the practice of real-world sailcraft
    The method seems to accept conventional signing of north and south
    latitudes, and east and west longitudes without so much as a hiccup.
    Under the category of "small things amuse small minds" it was so simple I
    could not resist playing with equal departure and destination latitudes 1'
    and 1" north of the equator, with longitude difference approaching 180d.
    Fun and interesting to see at which point it routed me over the pole instead
    of along an equatorial path.
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