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    DR vs EP vs MPP vs Fix vs Running fix
    From: Dave Weilacher
    Date: 2002 Feb 7, 14:28 -0500

    I've heard your definition before but it seems to make a distinction that makes no sense to me.
    Do you plot your compass heading and ignore known deviation and variation?
    If you know your speed log registers a 1/2 knot slow, do you leave this out of your DR plot?
    My guess is that you consider these into your plot because they are known to you.
    So... My boat sags off 5 degrees when sailing close to the wind.  I know this 
    from experience.  Why would I not include this in my DR.
    On a passage from Jacksonville, Fl headed for Bermuda, I know that I'll not be 
    remiss if I include 2.5 knots set to the north from when I hit 080 west 
    longitude till 079.20 west.
    Or better yet, if I don't adjust my heading for set between Ft lauderdale, Fl 
    and West End, Grand Bahama Island, I'll have a terrible time getting there.
    Original message.
    dave ,
    I was taught that DR is determined only by course (heading) and speed.
    windage, etc., get factored into EP, but not into the DR.
    Chuck Taylor
    > My definitions:
    > DR - Position determined by heading, speed, known windage, and known (for
    sure) set &
    > EP - Position on an unsubstantiated line of position that you may be at.
    Usually at the
    closest point of approach to DR.  It may also be where 2 or more lines of
    intersect, if you can't justify or explain the difference between that
    and your
    DR.  (this last comes out of Bowditch 1977).
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