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    Plotting in True
    From: Lu Abel
    Date: 2009 Jul 23, 20:49 -0700

    There are some dreadful time sinks on the net and one of them has got to
    be NOAA's collection of historical charts that Frank so kindly pointed
    me to.
    
    I came upon a 1882 chart of Woods Hole (called Woods Holl on the chart).
    
    The chart has an annotation that says
    
    "Note:  The Courses and Bearings without the Brackets are Magnetic,
    those within are True ..."
    
    Every single course and bearing shown on the chart is unbracketed.
    (They're also shown in compass points and not in degrees.)
    
    Somewhere along the line navigators were taught to plot courses in True.
    
    Plotting in True makes a lot of sense for ships equipped with
    gyrocompasses.   But it also requires repeated TVM calculations to use
    an ordinary magnetic compass.
    
    Does anyone know when plotting courses in True (rather than Magnetic)
    became the rule??   Would I have found such a requirement in, say, an
    1882 edition of Bowditch?
    
    Lu
    
    
    "Note:   The Courses and Bearings without the Brackets are Magnetic,
    those within are True ..."
    
    Every single course and bearing shown on the chart is unbracketed.    So
    there's some pretty strong historical precedent for showing courses in
    Magnetic!!!
    
    Lu
    
    
    
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