NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tom Sult
Date: 2015 Mar 25, 11:15 -0700
Tom Sult, MD
Carly:
I'm no expert, nor do I make any claims to expertese. That being said, the Davis sextant you mentioned, plastic frame, will work, I've used one, shooting the sun while standing on the beach in North Carolina, I don't have a boat and tend toward seasickness, so I "navigate" standing on the beach, or using an artificial horizon in the parking area at home. Due to materials of construction, these instruments will sometimes give "odd" readings, but they do work. By the way, have you tried the telescope for shots, youmentioned using a sight tube.
Eventually, while feeling flush, I bought an Astra sextant, metal frame, a much better instrument, though a lot more costly. Depends on how foolish one wants to be re spending their money. Your father could likely make some good suggestiis re a quality instrument, as could any number of people at NavList, it boils down to how much you want to or are willing to spend, thougth finding a "bargain" is always possible, perhaps but not likely, but possible. Good luck.
Alan