In a message dated 9/22/2004 1:42:50 PM Pacific Daylight Time, sh_at_actglobal.net writes: > Marking your position on a chart by ded reckoning > is an impossibility. After you are about 2 miles off shore, you won't see > enough detail for ranges behind you and you probably can't even see your > destination. > Ded reckoning is not just visual determination of position, it also may include time as an element, "by which a boats approximate location is determined at any time by its movements since the last accurate determination of position." (Chapman Piloting) If one has a reasonable understanding of group speed (say 3 knots), and marks off a 3 mile section at a break at the top of the hour, one will have an approximate position. No, not exact, but approximate. In vector navigation, where significant current requires an approximate ferry angle to help offset current strength and direction, will result in paddling a course line with hourly changes in bearing throughout the crossing. The reason this method is preferred by some, over other methods, is it enables an approximate position to be known. Rob G *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Wed Sep 22 2004 - 14:37:16 PDT
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:31:17 PDT