View Single Post
  #10   Report Post  
posted to rec.boats.cruising
Capt. JG Capt. JG is offline
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 7,757
Default celestrial navigation anyone?

"Wayne.B" wrote in message
news
On Sun, 20 Apr 2008 22:57:42 -0700, "Capt. JG"
wrote:

The advantage of this method is that it is incredibly easy to do. You
don't
even have to correct for refraction or dip. Even if your sextant has an
error, it won't matter.


Conceptually it works but has big issues in real life. As mentioned
previously accurate star sights are only available for a few minutes
at sunrise and sunset every day. The times of sunrise and sunset are
changing every day from both seasonal variation and also from your own
travel. And of course there are many days when no sights are possible
because of overcast weather.



You don't need accurate times for sunrise and sunset to make this work. You
don't need to be dead on accurate if you're doing emergency navigation,
which is what this would be good for. Getting close would be fine. And, you
can use any couple of stars at night.

--
"j" ganz @@
www.sailnow.com