Next message: Lu Abel: "Re: Plastic sextants and prejudice. was: GPS shortcomings."
What I'd heard from many sources (which doesn't mean it is true) is that the
Davis, and all plastic sextants, suffer more from thermal changes in the
material than metal sextants. Supposedly taking it out from below decks and
letting it heat up in the sun will throw the index error out more than it
would with a metal sextant.
But in theory a good navigator would allow a sextant to acclimate to
heat/cold and then recheck the index error before using it. Perhaps it is
bad habits that give it the bad rep?