NavList:

Gary:

 

You wrote:

 

Why not just cheat?
 
For the short period between the two observations simply change your
course to straight east of  west, that eliminates the problem of vessel
movement. Even better, adjust the course slightly north or south of
east or west to create a vector north or south movement to compensate
for the change in declination of the sun.

 

I'm a sailor and course changes are not trivial, and usually dependent on the wind. I've never worked for a captain who would change his course for an hour for the convenience of the navigator. As a backup to GPS, the method would be used  in emergency conditions, when arbitrary course changes would not be prudent.

 

And:

 

 

The advantage over calculating lines of position is that there is no calculating. The arithmetic involved is only addition and subtraction. I note in the referenced paper that "Since plotting runs of sights is always recommended, no extra work is involved there, and the few computations are significantly less than reducing a pair of sights and plotting them to get a fix." And now there are no computations at all.

 

Thanks for your interest. In my classes, I encourage questions, since others may benefit. Your opinion may well be shared.

 

Jim Wilson