NavList:

   

Reply

I, too, agree that this is a valuable technique.  Imagine aiming for a
harbor after a long voyage.   If you are somehow thwarted in getting
precise enough positioning as you end your voyage and come upon the
coast line, which way do you turn to find the harbor??   But if you
deliberately aim to one side of it, you know which way to turn and run
along the coast.

Before GPS and before reasonably priced Loran-C, I used this technique
many times approaching Nantucket Harbor.   There are shoals projecting
into Nantucket Sound at both ends of the island.   Sticking to the
channel in Nantucket Sound, you have about an six mile run south to the
harbor entrance after leaving the appropriate buoy in the channel.
There are no intermediate buoys.  Somehow the sea gods decided that
every time I made the turn it was time to bring in the fog.
Fortunately, the coast of Nantucket just gradually shallows out.  The
entrance buoys for the channel into the harbor are on the 12' contour.
I simply deliberately aimed 1/4 mile to one side or the other of the
entrance, picked up the 12' contour (adjusted for height of tide, of
course) and ran parallel to the coast until I picked up the harbor
entrance.

Apache Runner wrote:
> Yes, this is actually a pretty common technique.   The main issue is
> that finding a line is much easier than finding a point.    I've heard
> this referred to as "deliberate compass error", but it's the same idea.
>
> Finding a one dimensional object - a road, a river, a coastline, etc
> is easy as long as you know the general heading to that.   If you have
> a specific heading to a location that lies along that
> river/road/coastline/trail, you make a deliberate offset, so that when
> you come across that river/road/coastline/trail, you know which way to
> follow it in order to make it to your destination.
>
> I've done this numerous times, kayaking in the fog off the coast of
> Maine.   I might want to his a point on the easternmost side of an
> island, but if I miss that, I'd end up paddling out into the open
> ocean in the fog, which isn't a good idea.   So, I make a course for
> the shore of the island, knowing that once I reach it, I only head
> east.
>
> Gatty's example in Siberia is one of many.   This is definitely up my
> sleeve in my bag of navigational tricks.
>
> It reduces the two dimensional problem of navigation across a surface
> to a point to a one-dimensional problem.
>
> >

--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply