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18-10-2011, 21:53
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#61
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Registered User
Join Date: Dec 2009
Location: Bundaberg, Qld.
Posts: 2,192
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by Vasco
Interesting, didn't think they'd keep that going. Does the Second Mate wind all the ship's clocks every Sunday too?
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He changes the battery when they go flat, I haven't seen a wind up clock in years....
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19-10-2011, 03:39
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#62
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Registered User
Join Date: Mar 2009
Location: Homer, AK is my home port
Boat: Skookum 53'
Posts: 4,042
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Re: Celestial Navigation Help Needed
I have one aboard my vessel, but she is so inaccurate I wouldn't dare use it for navigation.
__________________
" Wisdom; is your reward for surviving your mistakes"
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19-10-2011, 20:37
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#63
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Registered User
Join Date: Sep 2010
Posts: 4
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by Jimbo485
4 seconds of time is 1 minute of distance (ie. 1 mile). So your error is 0.00675 miles. FA.
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4 seconds of time is a minute of longitude.
Close to the poles, it is a fraction of an inch.
At lat = 0, then it would be a mile.
Just a though.
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21-10-2011, 09:00
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#64
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cruiser
Join Date: May 2011
Boat: cornish crabber
Posts: 54
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Re: Celestial Navigation Help Needed
hello there,
is there any link to download polaris (pole star) tables in pdf.
i downloaded nautical almanac from this site
navsoft.com/almanac.html
but there is no tables for polaris sight
thanks
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21-10-2011, 09:37
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#65
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Registered User
Join Date: Aug 2010
Location: Naples, FL
Boat: Leopard Catamaran
Posts: 2,572
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by epilot10
4 seconds of time is a minute of longitude.
Close to the poles, it is a fraction of an inch.
At lat = 0, then it would be a mile.
Just a though.
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Even a years worth of error will allow me to hit a 50mile Dia island.
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21-10-2011, 09:40
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#66
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Registered User
Join Date: Aug 2010
Location: Naples, FL
Boat: Leopard Catamaran
Posts: 2,572
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by gravosa
hello there,
is there any link to download polaris (pole star) tables in pdf.
i downloaded nautical almanac from this site
navsoft.com/almanac.html
but there is no tables for polaris sight
thanks
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Isn't Polaris a straight sight angle? I.E. at (north pole = 90, at equator = 0) - altitude of observer.
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21-10-2011, 09:55
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#67
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Moderator Emeritus
Join Date: Oct 2009
Location: Manchester, UK
Boat: Beneteau 473
Posts: 5,589
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by capn_billl
Isn't Polaris a straight sight angle? I.E. at (north pole = 90, at equator = 0) - altitude of observer.
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Not quite, Polaris orbits a circle around the celestial pole
See
Convert A Polaris Sight To Latitude
__________________
Nigel
Beneteau 473
Manchester, UK
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10-11-2011, 12:19
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#68
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Moderator Emeritus
Join Date: Oct 2009
Location: Manchester, UK
Boat: Beneteau 473
Posts: 5,589
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Re: Celestial Navigation Help Needed
Quote:
Originally Posted by gravosa
hello there,
is there any link to download polaris (pole star) tables in pdf.
i downloaded nautical almanac from this site
navsoft.com/almanac.html
but there is no tables for polaris sight
thanks
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If you still need/want the Polaris Correction tables, let me have an email address and I'll send you scanned copies from the 2011 Admiralty Nautical Almanac, I'm back at work and now have the book to hand
__________________
Nigel
Beneteau 473
Manchester, UK
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