NavList:

Many thanks Greg for taking the time to inspect and analyse my set of sites.  The times of the sights are the uncorrected deck-watch times.  That is for me a lesson learnt - specify not only the time zone, but if it is corrected time or not.

One of the great things about celestial navigation, is that you are always learning.  I'm a novice, and was perplexed that there was usually something strange about my series of sights taken for solar noon.  These readings would be taken  over a 40 minute period. When graphed out, the parabola was usually slightly distorted and when on an Easterly course the estimated longitude was inaccurate.  The answer (which is probably obvious to most reading this post) was found in Peter Hakel's post of June 10th announcing the release of Astron v 1.14.  In that post Peter writes "Utility added to refine upper meridian passage sight for ship’s velocity and body declination change rate."  It is going be interesting to review those noon sights with the ship's course and speed taken into consideration.

Again, many thanks.

David.