Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-06-2006, 09:36   #31
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
Celestial Navigation can be as complex or as simple as you want to make it. Total understanding of why we add different corretions is nice to have, just as being able to do the calculations using Haversines etc like they did in Nelson's day.

However, they are not essential to being able to find your position.

Tom Cunliffes book shows the minimum necessary to be able to do just that
__________________

__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 18-06-2006, 11:58   #32
Senior Cruiser
 
SkiprJohn's Avatar

Cruisers Forum Supporter

Join Date: May 2006
Location: Kea'au, Big Island, Hawaii
Boat: Cascade, Sloop, 42 - "Casual"
Posts: 14,192
Aloha Zach,
As posted a few back most books I've read contain the same information. I'm not familiar with the one you mention but if it easy for you to understand then it will be a good book. My way of "do-it-yourself" in all aspects of life is that I buy 3 books and pick out the one that explains my project in the simplest but detailed manner and go with that one.
I don't buy new books. I shop at used book stores or yard/tag/garage sales.
Some books touted as celestial navigation deal with calculators or other electronic devices. I don't read those books but go with the more traditional methods using the Nautical Almanac and Sight Reduction Tables for Air Navigation (H. O. 249).
The meridian passage or noon sight which Talbot and I have been talking about only requires a sextant, a watch, the Nautical Almanac and a good form to fill out.
If "Practical Celestial Navigation" covers the concept of determining latitude and an approximate longitude by means of a noon sight/meridian passage then it will be a useable book.
I'll be looking for Tom Cunliffe's book as recommended by Talbot but my selection here on an island is a bit limited. Maybe I can find it used on Amazon.com. Good luck and--
Kind Regards, --John--
__________________

__________________
SkiprJohn is offline   Reply With Quote
Old 18-06-2006, 13:33   #33
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
Dont know about Amazon, but its 8.95 from the RYA. for his Celestial Navigation.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 18-06-2006, 13:49   #34
Senior Cruiser
 
Vasco's Avatar

Cruisers Forum Supporter

Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore" Ben393 "Breathless"
Posts: 7,137
Talbot,

I used the haversine method when I went to sea and I assure you it wasn't in Nelson's days as I think I'm still alive. We were not allowed to use any shortcuts such as HO 249. We were required to know the principles of navigation rather than "filling in the blanks" in a form. Why, I don't know except that traditionally, that was the way it was. I hated spherical trigonometry having flunked math most of my school days. The hardest part of navigation is bringing a body down to the horizon especially in a small sailboat. The rest is just "filling in the blanks" if you've got the right forms.
__________________
Rick I
Toronto in summer, Bahamas in winter.
http://groups.yahoo.com/group/beneteau393/
Vasco is online now   Reply With Quote
Old 18-06-2006, 18:21   #35
Registered User

Join Date: Jun 2006
Posts: 559
this is a very interesting/good post. so glad to here people still believe in the use of sextants ect. i will be learning how to use one myself for when we go off in a 1yr or 2. SkipJohn thnks for the book info i already have two that my dad says are really good, but for me a little intimidating. Dad was a capt for Ned-Loydd in the 50s and i inherited his sextant. he tried to show how to use it when i was young but you know how kids are.

regards to all! Mike
remember sail fast-live slow
__________________
mike d. is offline   Reply With Quote
Old 18-06-2006, 20:37   #36
Senior Cruiser
 
SkiprJohn's Avatar

Cruisers Forum Supporter

Join Date: May 2006
Location: Kea'au, Big Island, Hawaii
Boat: Cascade, Sloop, 42 - "Casual"
Posts: 14,192
Aloha Mike,
Ask any questions here and you're certain to get answers. If you inherited a sextant from a Captain (your father) it is bound to be a good one. It would be nice and honor his memory to learn to use it. Vasco made a point. Celestial can be intimidating if you try to learn the really hard way.
Regards, --John--
__________________
SkiprJohn is offline   Reply With Quote
Old 19-06-2006, 03:17   #37
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
Mike, part of learning how to use a sextant is removing the errors that are inherent in any sextant. The book that I referred to above (Clestial Navigation by Tom Cunliffe provides the best description of these errors and how to remove them, that I have ever read.

I also inherited my fathers sextant (used during the second world war), and will soon need to get the mirrors re-silvered. luckily there is a company near me that specialise in this area.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 06-01-2008, 20:03   #38
Senior Cruiser
 
SkiprJohn's Avatar

Cruisers Forum Supporter

Join Date: May 2006
Location: Kea'au, Big Island, Hawaii
Boat: Cascade, Sloop, 42 - "Casual"
Posts: 14,192
Aloha All,
Last Friday night I conducted my second class in "an Introduction to Celestial Navigation." I find it very interesting that folks still want to learn this even though GPS has really taken all the "fun" out of celestial navigation. It took us 3 hours to walk through the steps to find ourselves. It would have taken 5 minutes or less using GPS.
I teach it because people want to learn and at the cost of $3.00 it is affordable to them. All I do is walk people through a Meridian Passage/Noon Sight equation and how to use a sextant. I don't expect anyone to come out of the class really ready to do a circumnavigation. I really do expect everyone to start really appreciating the GPS, which they do.
As an old sailor I would hope that everyone would have a bit of curiosity concerning the "old way" of finding their way around the oceans. Its certainly not necessary and takes a lot of time but in case of power failure in a life raft, might help.
Kind Regards,
JohnL
__________________
SkiprJohn is offline   Reply With Quote
Old 07-01-2008, 02:15   #39
Registered User

Join Date: Jan 2008
Location: Queensland Aust.
Boat: last boat , compass28
Posts: 4
well I use an old davis plastic sextant , I'm always 5 miles out and I know I'm always 5 miles out so the care factor lies , I'm 5 miles out ,,
__________________
TonyQ is offline   Reply With Quote
Old 16-01-2008, 10:15   #40
Registered User
 
clausont's Avatar

Join Date: Mar 2007
Location: Pacific NorthWest
Boat: Sold - Landlocked
Posts: 561
Images: 60
I am just now starting to learn celestial navigation. After reading everything in this thread, I have a few direct questions. I had planned on buying a couple of books (much as SkiprJohn has said that he does when learning something new), sight reduction tables and a Nautical almanac. After looking for the last two items, I find that there are enough choices that I am having a hard time deciding exactly which to look for.
My question: Which books, sight reduction tables and nautical almanac would you recommend for an absolute beginner?
I do not know anybody in this area that knows celestial navigation that I can go to for help when I get stuck, so I think that good, easy to understand books will be important.
__________________

clausont is offline   Reply With Quote
Old 16-01-2008, 10:27   #41
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
One of the simplest books is "Celestial Navigation for Yachtsmen" by Mary Blewitt. It's widely available in most any bookstore.

As for the Nautical Almanac, be sure to get either the genuine US Government pub, or one of the commercial versions of it. NOTE: the widely popular Reeds Nautical Almanac no longer contains almanac data. It's title, therefore, is very deceptive (and they don't care...I talked to a rep about this at the Boat Show in Annapolis).

As for the sight reduction tables, most sailors prefer HO 229 or HO 249. I'm one who prefers HO 214. Any of these will do fine...it's just what you get used to.

If you'll shoot me an email to: bill at wdsg dot com

I'll be happy to send you some forms I've worked up for sight reduction. It would be good to start with the very useful Noon Sight for Latitude, then the Noon Sight for both latitude and longitude.

Congratulations both on your desire to learn celestial nav, and on your determination to go with "too small a boat". It's the going which is important, not the size of the boat :-)

Also, be sure to check out: Celestial Navigation Net

Bill
__________________
btrayfors is offline   Reply With Quote
Old 16-01-2008, 10:44   #42
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,033
Blewitt's book is the classic for "well, now that we're in the lifeboat, who's going to learn how to use the sextant today?!" It is eminently practical, simple, to the point.

For a bigger picture of navigation and the role of hte sextant in it, I'd suggest George Mixter's Primer of Navigation which basically covers the entire field, piece by piece, with equal clarity explaining how and why things have come about and work. A much longer but very enjoyable text.

And for the simple mechanics of "But am I doing this right?" Bill Buckley's video on basic sextant use, which walks you through using the sextant and running calculations with the tables.

Speaking of which...I know purists want to stick to paper tables, but having a sight reduction program on a dedicated calculator, or on a Palm (reliable, inexpensive) or a laptop means that you can double-check against your own math errors or just get a nice fast sight reduction.
__________________
hellosailor is offline   Reply With Quote
Old 28-12-2008, 21:24   #43
Registered User

Join Date: Dec 2008
Location: South-western Pennsylvania
Boat: no boat, I'm a "landlocked" navigator
Posts: 87
Quote:
Originally Posted by SkiprJohn View Post
Aloha All,

I am coming up with a really good noon sight form that anyone can use with a Nautical Almanac to find latitude and longitude. Let me know if you are interested and I'll make it available to forum members.
Kind Regards, --John--
Book Recommendation - Celestial Navigation by H. O. 249 - John E. Milligan
Re the above, excerpted from your post, I would like to see the form you mention.
Thanks.
alan2
__________________
alan2 is offline   Reply With Quote
Old 29-12-2008, 00:15   #44
Registered User

Join Date: Aug 2008
Location: Finland
Boat: OneOff ketch, 48 ft, s/y Oceania
Posts: 9
Images: 5
Dear John,
I did my celestial navigation course in Finland during 2003-2004 and found it really interesting.
However, an old friend of mine, professional skipper and sailor, told me that his friends used to ask him what they needed to have on a long voyage and he used to give this answer: "take a bag of gps's, some hand held too, an other bag of batteries for them, and keep the bags separtely, on a safe and dry place on your boat".
An other finnish skipper i happen to know, and who did his world around voyage 1993-1997, told me that celestial navigation skills are good and nice to have but just for fun and a nice way to spend some time on voyage.

best regards,
timo
p.s.
my celestial navigation instructor used also forms for everything
__________________
TimoVilla is offline   Reply With Quote
Old 29-12-2008, 12:09   #45
Senior Cruiser
 
SkiprJohn's Avatar

Cruisers Forum Supporter

Join Date: May 2006
Location: Kea'au, Big Island, Hawaii
Boat: Cascade, Sloop, 42 - "Casual"
Posts: 14,192
Aloha Timo,
GPS is very convenient, well respected and, so far, very dependable. I guess I keep my celestial skills up just for the mental exercise and in the eventuality that satellites stop working.
Good to hear from you.
Kind regards,
JohnL
__________________

__________________
SkiprJohn is offline   Reply With Quote
Reply

Tags
celestial navigation, navigation

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Which Navigation Program Do You Use? Shark Navigation 148 08-12-2009 17:50
Free navigation software JanPeter Navigation 33 17-04-2009 18:05
Should I print this?? Bob Norson Off Topic Forum 31 03-06-2006 06:39



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:17.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.