While beating into the wind you plot a series of course lines.


Why?

Joe wrote:
to know where you are, maybe avoid a coral reef ect....maybe.


And so you follow a DR course for 80 miles, not getting a
fix, in an area where there are coral reefs?

Yeah right.


Depends- over the course of 80 miles it is very likely... a
near certainty... that the current will have changed.

So you could never use that "Drawing a line between origin & present
DR" method again could you


Sure you could. It would allow perfectly for set & drift
over that time & distance... if set & drift were constant
the whole time you were sailing along with no fix & not
having plotted set & drift for each tack...


Some DR plotters include leeway, and with a full-keel boat
that's a good idea IMHO. It should be plotted for each tack,
not overall.

DR Plotters? The DR plotter is suppose to be in your head

Umm, no... it is perfectly acceptable to work a DR plot on a
chart. Or did you think I meant some electronic gizmo?

"DR Plotter" means the person who is plotting the DR.

Not you, in other words.

DSK