TIP: If the seller says "brass sextant", there is an excellent chance that it is only a display reproduction of a real sextant
. Most are bronze
. Or aluminum
. I think a lot of posters here who mention brass sextant
, actually mean bronze
. Big difference. Most brass alloys are too soft for use in sextants.
Salvaged sextants from the shipbreakers are often an excellent buy. As another poster said, they are mostly very lightly used.
Half mile accuracy is pretty doable on a ship, but actually rather difficult on a small sailboat except in very calm conditions. Happily, a triangle that is 2 or 3 miles across is perfectly adequate for midocean navigation
Good idea to keep a notebook in a ziplock. Write your navigation
stuff in pencil. If it gets wet, it won't run the way ink does. Ask me how I know. If you always record
your hourly speed and course, and all your fixes, you can always reconstruct your plot, and you should know how to construct a plot sheet on blank paper.
I like the Astra sextants. Pretty decent instruments. The one and only one I have now is a vintage Plath scored on fleabay. Seems okay enough though honestly I have not had much opportunity to mess with it since purchase
. Davis plastic sextants are popular and we could argue all day about their suitability but while I respect the decision by many to go cheap
, I am personally firmly in the metal camp.
Sight reduction apps are nice but remember, you are dealing with computer or tablet or celphone or celestial calculator, and if you want an alternative with zero dependance on electricity or electronics
, you should know how to add and subtract manually, and use sight reduction tables. And keep them aboard, at least the relevant volume or volumes for your voyage, along with an almanac. My suggestion is work
it out longhand and check it with a sight reduction app, and then compare your final fix with the GPS
fix for the same time. You can also just always record
position and just see if lies on your LOP or not. Use all your resources and be a true navigator. Use only your sextant and you are merely a seagoing Luddite. Use only electronics
and well, I will stop right there. LOL!
Have pencils. Lots of them. Erasers too. Triangles. When you get used to using them, much faster and more accurate than parallel rules or fancy pants rolling rulers. Two pairs of dividers, not just one. You want to keep one with a pencil mounted, for use as a drawing compass
One of the most neglected skills of the navigator in small boats is compass
checking. This is one celestial task that at least on U.S. ships, is likely to be done daily. The quick and dirty way is to take an amplitude. Easy as pie. Even if you have NO sextant, you can do that, or do an azimuth. Creating a compass deviation card is satisfying and useful.
Another useful tool for the primitive navigator is a chip log. Much more accurate than just guessing your speed. Make it yourself!