GJordan has a point, yeah, but I take the opposite tack on this. I think it is better to take the baby step and learn to do a LAN (noon sight) first, because it builds confidence to be able to almost immediately do something very useful with your sextant
. And if you go no further well then at least you know how to find your latitude at Local Apparent Noon. That's all navigators had, for hundreds of years, and they usually managed. But I would think being able to determine latitude but not get a position, would make most users hungry for more knowledge, and they would at least want to learn how to take a morning or afternoon sight, reduce it to a Line Of Position, and advance or retard it to the noon sight, to get a fix. Just three observations a day of just one body, the Sun, is enough to get you across an ocean.
From that modest beginning, a motivated wannabe navigator would have a fairly easy time of learning
to do morning and evening stars. Moon is actually slightly more difficult, believe it or not, if you want accuracy. Just slightly more complicated. Moon and planets should come after stars, for a nice progression.
Not everyone wants to be Bowditch Junior. Some folks are okay with just being able to put a noon position down on the chart every day. Nothing wrong with that, especially if you are also teaching yourself to keep a good DR, which I think is even more important than having a sextant and knowing what to do with it.
I used to insist that any ocean navigator MUST be well practiced and knowledgeable at the art and science of celestial navigation. Redundancy is the sailor's friend. Two or more completely separate means of determining position should be at the top of the checklist for venturing out of sight of land, and between celestial and GPS
, its well covered. But I have moderated my stance slightly, in view of the fact that most folks have not only a "real" GPS
but also usually a smartphone with a GPS in it, and maybe a USB dongle, too, and multiple means of getting electricity to phone
, computer, and free standing GPS. The only weak point in the chain is the GPS system itself. If the North K***ns (don't want to start an international incident) or anyone else shot down or EMP fried all the satellites, then I guess a GPS-only navigator is thoroughly hosed. But otherwise, the study and practice of celestial navigation by the cruising yachtsman is slowly approaching the status of "hobby". It is a beautiful feeling to put a perfect pinwheel fix on a paper chart or plot sheet. The feeling of accomplishment is very gratifying, and there is a major cool factor in using such timeless navigation techniques. But it is less of an essential thing than it was only a few years ago, in the age of the dumb phone
, and before you could get a 40 watt solar
panel at Harbor Freight for the cost of a nice lunch. So, I submit that skipping over LAN and ex-LAN sun lines in order to ensure comprehensive learning
is maybe not the way for the average person to learn. YMMV of course.
Congratulations on your sextant. The Astra is quite a practical and usable instrument, certainly accurate enough if you do your part. The price
Probably the biggest dealer in Astra sextants in the U.S., Celestaire, also sells books
, some of which are good choices for a learner text, and some that are just plain interesting and entertaining. I had a book I bought from them (lost dirung Katrina) called "Celestial For The Cruising Navigator", that I rather liked. Taught me a few things, yeah. Not the simplest book, no, but interesting in its approach, which avoids the use of HO229 or HO249 altogether in favor of using an ordinary scientific calculator for sight reduction. This is a good thing to know, certainly. With a solar
powered calculator, and memorization of just a couple of formulae, and practice at converting minutes to fractions of a degree, you have a very good failsafe alternative to paper sight reduction tables or dedicated celestial calculators or tables saved to a computer. I don't have a lot of trust in laptop
hard drives, me. The vibration, pounding, etc can do bad things to a hard drive platter. And paper tables take up a lot of space, though to be fair most of the time you only need one or at most two volumes to cover the latitudes you will sail in. But knowing those formulas and having a number cruncher is pretty reliable. Anyway I thought I would throw that excellent book in the mix. Wasnt hard to understand, and getting in to the math (no, you don't have to be good at math to do this, just patient and careful) a little, helps you to truly understand how and why it works. Just pulling data from 229 and the almanac and going through a cookbook
method works, but doesn't really make you feel anything.
On the subject of almanacs, yes, download. But when you download, you only get the daily pages. There are lots of tables and stuff that you have to get separately. Best to buy an almanac, and when it is out of date at the end of the year, you got hard copy of everything relevant except the daily pages. Download them. What did I say about computers
? Oh yeah. They break. So download the whole year so you got it, but also print the daily pages for the duration of your voyage. A hard copy and a computer copy... remember that redundancy thingie? Speaking of which, I do hope that you have a 64GB USB thumb drive for backing up stuff. They are pretty much immune to normal shock and vibration, a great place to keep an extra copy of programs, waypoints, daily pages, digital charts
is your friend. Here is a little tidbit of knowledge for you.
CELESTIAL REASONING: Quick & Dirty Noon Sights
So maybe you don't even need a book?
Longitude by chronometer - Wikipedia, the free encyclopedia
Astro Navigation: All you need to navigate by the Sun; Almanac, Sight Reduction Tables.
A couple more. Just to illustrate the treasure of knowledge you can find online. Never mind the youtube videos.
Anyway welcome to the dark side. And HAVE FUN with your sextant. Yeah navigation is serious business but it can be lots of fun too.