NavList:

Martin, you wrote:

• Objects with northern declination rise toward the northeast, with a rising azimuth of approximately 90° minus their declination.
• Objects with southern declination rise toward the southeast, with a rising azimuth of approximately 90° plus their declination.

Yes! But these can be combined. The idea that we have to list separate rules for northern and southern declination is now obsolete. South dec is negative, just as south latitude is negative. Given that mathematical fact, The rule is shorter, simpler: rising azimuth for observers at the equator is 90°-dec. Or, if we use the terminology of "polar distance", which still has a place in modern celestial navigation, then the rising azimuth is the polar distance (Azm=pd, where pd=90°-dec and dec is a signed quantity). Similarly and symmetrically, setting azimuth is 360°-pd. 

You described this as being "approximately" true. It's a very close approximation, and it may not even be worth mentioning that there is any "approximation". I'll write more on that in another post...

You added:
"Last year, during the March equinox, I had the privilege of standing directly on the Equator line near Nairobi, Kenya. I witnessed the Sun rise almost exactly due east, ascend vertically to nearly 90° altitude at transit, and set nearly due west."

Yes, I remember you telling us about that! It must have been a satisfying thing to see, in the context of celestial navigation. :)

Frank Reed