Re: celestrial navigation anyone?

"Jeff" <jeff@xxxxxxx> wrote in message news:fui7jo$t74$1@xxxxxxxxxxx
Capt. JG wrote:
...

The disadvantage is that each position depends upon the previous one, so
that small errors may build up to be large ones.

No, you can go a number of days referencing the last fix.

Don't understand... yes, you can go a number of days, but after that it
seems to me it would start to get way off.


If you are on a long voyage, you may find that the original stars are no
longer visible at a time when they are useful.

Yes, this is a problem.

Thus, I good idea to take several batches of stars in your observation, so
you can fall back on a second or third set.


Before this happens, you will need to pick some new stars, and take a
double round of sights - one for the fix, and one to establish a basis
with the new stars.

The other problem is that getting the compass bearing of a star is not
that easy.

Well, yes... that hard any time...

I would recommend that anyone interested in emergency celestial navigation
get a copy of "Particularized Navigation: How to Prevent Navigational
Emergencies" by Francis Wright, which shows how to do "good enough"
navigation with paper sextants, etc. Unfortunately, its long out of
print, so a bit of work would be needed to adjust some of the tables to
current dates.

BTW, I own three sextants (two WWII vintage, one antique) plus two
"lifeboat" sextants, but I haven't taken a sight on board in a dozen
years.


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



.

Relevant Pages

  • Re: celestrial navigation anyone?
    ... stars, and take a double round of sights - one for the fix, and one to establish a basis with the new stars. ... I would recommend that anyone interested in emergency celestial navigation get a copy of "Particularized Navigation: How to Prevent Navigational Emergencies" by Francis Wright, which shows how to do "good enough" navigation with paper sextants, etc. ...
    (rec.boats.cruising)
  • Re: Navigating by the Stars--Simple Methods?
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  • Re: could have used the stars all along?
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  • Re: could have used the stars all along?
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