NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
DR vs EP vs MPP vs Fix vs Running fix
From: Dave Weilacher
Date: 2002 Feb 7, 14:28 -0500
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. Current, windage, etc., get factored into EP, but not into the DR. Regards, Chuck Taylor > My definitions: > > DR - Position determined by heading, speed, known windage, and known (for sure) set & drift. > > 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 position intersect, if you can't justify or explain the difference between that position and your DR. (this last comes out of Bowditch 1977). About mail2web Terms and Conditions Privacy Policy Help -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .