Thank you Tyler. You describe a well-reasoned use for what I think is a somewhat vestigial holdover from the Nautical Almanac’s dim past. I did find in my own research (aided by others as well) that it is there to predict the Meridian Passage of a star. But I had not yet taken it to the practical aspect that you’ve done. It may also be true that when the NA gave star positions not with SHA & Declination but with Right Ascension & Declination there was a simpler “quick scan” to be had (still working on this). Do you mind if I forward your explanation (with credit to you of course) to my circle of celestial navigation friends who are also researching this?