Cheap Sextant/Astro Nav book

[lustyd]

Hi all, I'm considering a sextant as a xmas pressie for me from family. Budget is up to £100 so the pretty boxed ones are a no go.
I'm not travelling around the world just yet - this is purely for learning and fun.
I've seen the standard mk3 in Force4 for £55ish but wondering if there is a better option around anywhere. I'm assuming all of the brass ones around £70-80 will be useless for actually navigating/getting a proper fix?

If the mk3 is the recommendation then I could use the remaining budget for books etc. to learn from. Any recommendations here would be welcome too. I have Tim Bartlett's book but found this quite hard going (sorry Tim!). Given that his nav book was excellent does this mean that there won't be a better book? Again recommendations welcome.
Cheers
Dave

 

[TQA]

Any cheap plastic sextant will do, I used an Ebbco for years and found my way about the Atlantic with it. They turn up on Ebay and may still be available new.

Celestial Navigation for Yachtsmen by Mary Blewitt is a good book to start with. No unnecessary theory.

 

[snowleopard]

The sub £100 brass ones are pretty unlikely to be any use. Some don't even have a scale engraved on them! The first thing to look for is whether it has a micrometer drum - most old ones and ornamental replicas don't have a drum.

 

[Skylark]

The cheap brass ones are ornamental only. The cheap plastic ones work. I, too had an Ebbco which I bought in the 1990's and sold recently on Ebay for just £20. I'd taken a number of sun sights with reasonable accuracy with it. I still have a Davis plastic one and my present-day pride and joy is a C&P Sailing Sextant. That came with an eye watering price tag.

I think theory books become personal preference depending upon how your grey matter functions. I did the RYA shorebased course intensive, one-to-one with a master mariner but didn't take a sight at sea until a few years later by which time I'd pretty much forgotten the theory.

I bought the Adlard Coles Ocean Yachtmaster text book and systematically worked through it chapter by chapter. This helped my learning and understanding.

I also have the Tom Cunliffe text book but I didn't like it as a primary learning aid as, for me, it didn't go deep enough with its explanations.

If I consider Tom's book a summary of the Adlard Coles then the Mary Blewit is a summary of Tom's, IMHO.

Once you're hooked, you can buy The American Practical Navigator by Bowditch. You can download this for free but if you're attracted to celestial navigation you'll most certainly appreciate a real book!

Then you can buy a nautical almanac, AP3270 vol 1,2 and 3 and Norries Tables make a good addition to your library.

Doubtless others will have a different view but the above represents my first hand experience.

Good luck.

 

[Neil]

Then you can buy a nautical almanac, AP3270 vol 1,2 and 3 and Norries Tables make a good addition to your library.Good luck.

You can download the three volumes of AP3270 for free too, as well as the current year's almanac

 

[sarabande]

have a quick look on ebay. Ebbcos all start at £20 is, and you may be lucky to get a BIN for a Freiburger (as I did for £75)

 

[lustyd]

Thanks all, once again an amazing amount of info!
Cheers
Dave

 

[RobBrown]

Alan Murray, who has posted on here from time to time previously sent out an adobe proof copy of his new Astro-Nav book and altho I have only read from theory pov (as I haven't got round to getting a sextant yet!), I found it a very good guide, comprehensive and comprehensible.

Its called Astro-Navigation from Square One to Oceanmaster by Alan Murray

Available from Authors Online, including in e-book format, which is £3.95

http://www.authorsonline.co.uk/book...from+Square+One+to+Ocean-Master+2011+Edition/

No connection, other than as a reader!

 

[RobF]

The cheap brass ones are ornamental only. The cheap plastic ones work. I, too had an Ebbco which I bought in the 1990's and sold recently on Ebay for just £20...
.

Thanks Dave - I was the buyer of your Ebbco

With regards to books, my personal preferance is 'Celestial Navigation - A step by step self teaching course' by Gerry Smith.

I would also recommend having a look at Abe Books - I bought the Mary Blewitt book for less than £5 (including postage).

 

[lustyd]

You can download the three volumes of AP3270 for free too, as well as the current year's almanac

Hi Neil, where are these? All I can find are the forms that go with them.
Thanks
Dave

 

[snowleopard]

If you are planning to learn astro for a backup there are various shortcuts you can take. The textbooks will tell you how to use sun, moon, planets & stars. They will cover northern & southern hemispheres and positive and negative declinations and all the corrections required to cope with them.

For professionals and those doing it as a hobby that's all very well but to get you home when your gps dies, you can manage perfectly well with just noon sun and a basic sun position line. If like most of us you are only going to be sailing in the North Atlantic in summer, all your latitudes and declinations will be North so a lot of the corrections and options drop out. A simplified sight reduction form specific to northern hemisphere summer makes the calculations easier. It also means you only need one book of sight reduction tables, vol 2 or 3 depending on your cruising latitude.

 

[lustyd]

Thanks, the truth is I will probably not be using it for years so this is just a bit of a hobby and one of the few areas still blank in my sailing knowledge. It's also partly down to not knowing what else to ask for for Christmas from my mum and it's either a sextant or some sidelining and I figure the manky carpet can last a few more months at least

Deciding which book to buy, I assume it would be vol 3 for home in GB? I've not read a lot yet but I'm guessing that north and south are irrelevant as far as the info in these goes?
Cheers
Dave

 

[stephenh]

lustyd

If you buy a hard copy of Vol 3 it is worth considering the US version, especially the 'private' copies, e.g. :

http://www.bookharbour.com/almanacs...r-navigation-vol.3-lat.39-to-89-decl.0-to-29/

Cheaper than the Admiralty ones and more to the point they are smaller in size;the Admiralty vols. will need a special bookshelf on your boat!

FWIW I found Wilkes 'Ocean navigator' the best for learning astro - well written, good diagrams and includes the use of traverse tables which all the others appear to avoid.

Good luck

 

[Skylark]

Thanks Dave - I was the buyer of your Ebbco

With regards to books, my personal preferance is 'Celestial Navigation - A step by step self teaching course' by Gerry Smith.

I would also recommend having a look at Abe Books - I bought the Mary Blewitt book for less than £5 (including postage).

I hope the Ebbco serves you well; it did for me. Last time I used it was on an 800 miles Biscay crossing. I kept a running fix of forenoon, MP and afternoon sun sights. Slightly amusingly, as we progressed south, index error increased pretty much in line with ambient temperature!

I haven't seen the Gerry Smith book but I used his Coastal Navigation self teaching book many years ago. That book was praiseworthy, IMHO, so assuming it follows the same logic his astro one is probably a good source of reference.

Once you have a grasp of the theory, it's all about putting it into practice. Sun sights are relatively straightforward but you'll need good optics to find the very-far-away tiny things predicted by Vol 1 to be overhead at your local twighlight.

On our Irish Sea summer cruise this past season I tried to take a couple of sights and derive a PL each day......the weather, of course, had other ideas.

 

[Neil]

Hi Neil, where are these? All I can find are the forms that go with them.
Thanks
Dave

From Here: http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0012

I printed and bound the whole whack, but you really only need your expected latitudes.

Almanac from here: http://navsoft.com/downloads.html

Also increments and correction tables from there too. The almanac is protected but you can unlock it online

You can download Bowditch from msi.nga.mil too!