On Sun, 20 Apr 2008 22:57:42 -0700, "Capt. JG"
wrote:

The advantage of this method is that it is incredibly easy to do. You don't
even have to correct for refraction or dip. Even if your sextant has an
error, it won't matter.

Conceptually it works but has big issues in real life. As mentioned
previously accurate star sights are only available for a few minutes
at sunrise and sunset every day. The times of sunrise and sunset are
changing every day from both seasonal variation and also from your own
travel. And of course there are many days when no sights are possible
because of overcast weather.