NavList:

Jim Thompson wrote:
”Jeff, this might help:

http://jimthompson.net/boating/CelestialNav/CelestNotes/Sailings.htm”

That’s a rich resource Jim has provided.

It seems to me that there is a trade-off between simplicity and accuracy, and in the end the user has to decide which method is appropriate.

The simplest method is to measure on the chart, and this may well be accurate enough for many practical purposes.

Next (less simple) is possibly Plane Sailing, followed by methods like Mid Lat.

The most accurate method uses both Meridional parts and Meridional differences. This takes account of the irregularities in the spherical-like shape of the earth. Using Meridional tables and (relatively) simple formulae, this method is quite easy to get used to using.

But this method is still not entirely accurate, as the mathematical models it uses can never be exactly the same as the irregularities in the earth’s shape.

This doesn’t matter much, for most navigational purposes.