The leg that crossed the equator or the 180 meridian was always one of the
downline points, loaded enroute, and a wrong entry would result in a wrong
way turn.

By using paper charts, a compass, and dead reckoning as backup, I mean
to actually use a plotter, draw a line on the chart, and measure the
course line. Your paper chart indicates (for example) a desired course
of 170, and your GPS says 190. Something's wrong.

It's like working a calculator without doing a rough calculation in your
head at the same time. Press one wrong button and the calculator will
tell you that you have 143,226.21079 gallons left in your 152. I'm
amazed at how many people would just put that down as the answer these
days, because the calculator said so.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain."
(chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.