[nauticalrich]

I remember reading in a most fastenating book, the biography of Tanya Aeibi and the story of her adventures sailing alone around the world. In it she used a sextant and could never get it to come out correct. After a great length of time trying to learn what she was doing wrong, Tanya finaly realized the plastic sextant was wharped. So much for accuracy.
Please forgive the spelling of Tanya''s name.
She is a contributing writer for sailnet.
I also recommend reading her book.