This is a very old thread, so the poster has probably made his/her decision.
I hope so! But the thread lives on, and may perhaps be of some use to others.
If as an emergency piece of kit, a decent plastic one would likely suffice.
Agreed. And plastic can also be appropriate as a 'starter' sextant. Per Budlong,
Sky & Sextant:
Many people start out with a plastic sextant for practice. After they’ve had some experience and know what to look for, they graduate to a brass one. I think this makes sense. They haven’t invested a lot of money right at first, and in the end they have a good sextant for regular use, and the plastic one as a spare.
Some navigators never "graduate" to a metal sextant, and of course that's fine too.
Leo Goolden used an old Ebbco for his 2015 transatlantic and had no issues (though
Tania Aebi wasn't quite so lucky!).
[A]nd, within reason, money makes a difference. Taking a sight with a good well made traditional sextant is just a joy.
I agree, Dick: top-quality sextants are a pleasure to use. And as a bonus, Budlong claims that mere possession increases one's longevity!
The quality and workmanship in one of these machines is something to behold. Just having one in the house will add joy to a rainy day and a couple of years to your life; using one is an experience in precision.