Not sure what you mean about not being able to use it at night... What about
the artificial horizon common on modern sextants?

http://en.wikipedia.org/wiki/Sextant

I'm somewhat familiar with the Davis models... thinking about playing around
with the 25.

I have a Carl Zeiss "Yachtmaster" which does not have any artificial
horizon and have yet to see a marine sextant that does. Bought it
second hand in its wooden box 20 years ago for NZ$450.

For sight reduction tables for sun, moon and stars I now use my O2
phone/PDA with a neat little programme (Bruce, please note the CORRECT
and civilised spelling of "programme"). Yes, I know, a lightning
strike could take that out too but I throw it in the oven with the
some of the other gear when lightning gets too close. Anyway, there is
always the backup of donning knee pads and grovelling to God.

About once a year I get the urge to keep up my skills in case of such
as a lightning strike, turn off all instruments for a few days and
take sights.

Peter