On 2007-09-16 16:36:13 -0400, roger said:

Why not rise above the crowd and learn celestial navigation. It is not
an obsolete skill and people respect those that know how to do it even
if they won't admit it.

Didn't Annapolis stop requiring celestial navigation a year or two back?

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

wrote in
:



The original poster was asking if he HAD to learn celestial before
starting off on his world tour and frankly (I'm about half way around
on most people's trip) I have never talked to anyone who actually used
a sextant to navigate. I have talked to people who had one aboard but
if you ask them whether they actually use it they sort of grin and
admit that "no, they don't".

Bruce in Bangkok
(brucepaigeATgmailDOTcom)


G The point to be made is not necessarily whether you use it (except
as an exercise or to have some fun, why bother) the point is can it be
of value should Mr. Murphy blah, blah, blah.
His statement regarding buying a cheap sextant and the particular book
was a valid idea which would give him that one more level of
protection/ability, should......

BTW you don't need an "accurate clock" to use a sextant, but speaking of
"time" most any modern (or old, for that matter)watch keeps accurate
enough time that it could be used, especially if you checked it prior to
"doomsday"
Jeff...accurate clocks were being used on many ships, long before
radio....radio just made it easier to monitor the rate

otnmbrd wrote:


BTW you don't need an "accurate clock" to use a sextant, but speaking of
"time" most any modern (or old, for that matter)watch keeps accurate
enough time that it could be used, especially if you checked it prior to
"doomsday"

My father-in-law was torpedoed at the end of WWII and spent 18 days in a
liferaft. They were able to track their longitude quite well because as
the radio officer he knew the error of his watch.

http://www.sv-loki.com/Davis/Clippings/clippings.html
more stuff at
http://www.sv-loki.com/Davis/davis.html

Jeff...accurate clocks were being used on many ships, long before
radio....radio just made it easier to monitor the rate

Agreed that many ships had clocks, especially larger ships and warships.
But a huge number did not, and I would guess that a large majority of
coastal shipping and fishing boats only rarely (if ever) had a celestial
fix.

Jere Lull wrote in news:2007091720575416807-
jerelull@maccom:

On 2007-09-16 16:36:13 -0400, roger said:

Why not rise above the crowd and learn celestial navigation. It is not
an obsolete skill and people respect those that know how to do it even
if they won't admit it.

Didn't Annapolis stop requiring celestial navigation a year or two back?


EG Annapolis is Navy..... not professional mariners.....nuff said

jeff wrote in
:

otnmbrd wrote:


BTW you don't need an "accurate clock" to use a sextant, but speaking
of "time" most any modern (or old, for that matter)watch keeps
accurate enough time that it could be used, especially if you checked
it prior to "doomsday"

My father-in-law was torpedoed at the end of WWII and spent 18 days in
a liferaft. They were able to track their longitude quite well
because as the radio officer he knew the error of his watch.

http://www.sv-loki.com/Davis/Clippings/clippings.html
more stuff at
http://www.sv-loki.com/Davis/davis.html

Jeff...accurate clocks were being used on many ships, long before
radio....radio just made it easier to monitor the rate

Agreed that many ships had clocks, especially larger ships and
warships.
But a huge number did not, and I would guess that a large majority
of
coastal shipping and fishing boats only rarely (if ever) had a
celestial fix.



BG Been a while since we had a discussion...... At any rate...... many
coastal vessels and fishing vessels would not need to use
celestial....here, you would need a historian to give you an accurate
reading as to the how and who did what (I'm not him/her)
BG Going to be on the Cape from 26th to 1st....if you get to Hyannis,
look me up (try the Black Cat)

jeff wrote in news:Y-
:

ts surprising how many of the old timers actually didn't know
celestial.

Wouldn't the time be better spent learning how to USE that new navigation
program running on the laptop than screwing around with your astrolabe?

Most sailors I know have no idea how to use the nav program running on
their boat....beyond using it for a chart that plots itself and the
simplest of map programs.

Sure is neat to see all those AIS targets now placed on the chart plotters
on Lionheart...(c; That electronics guy has everything working great, now!

Larry
--
Search youtube for "Depleted Uranium"
The ultimate dirty bomb......

On Sun, 16 Sep 2007 22:00:26 -0400, Red wrote:

brucepaige wrote:
How come all the advocates of a relative low tech method of
determining a position never mention that the system is unusable for
navigation in tight spaces, narrow channels, etc. and dead reckoning
or taking sights or measuring depth will be necessary.

I never hear anyone recommend having a lead line on board in case your
electronic depth sounder fails or a chip log mounted on the stern
pulpit in case your electronic speed log fails.

I see a number of arguments in this discussion. Fist, GPS recievers,
like all electronics are prone to occasional errors and failures. There
are numerous stories that abound in cruiser's logs on the net of GPS
readings that reported the boat to be a half mile or so inland, or in
the middle of a channel but the boat hits a charted reef, etc. There
are perhaps hundreds or maybe thousands of places around the world that
have innacurate GPS coordinates or innacurate maps used for the GPS
data. The Garmin chartplotter on the boat I usually sail on shows us on
land when we are in the middle of the channel in home port (and yes, the
settings are correct for the charts). So other forms of measurement are
always appropriate to know. And like it or not, the Pentagon did shut
down the satellite system for one day, and can do that anytime again,
not to mention the likelyhood of the system having problems as the
satellites age. And since I both sail and work on boats I can tell you
that both the depth sounders and speed logs do fail with amazing regularity.
Red

Yes, electronic devices fail and sextants get dropped knocking the
mirrors out of alignment.

Yes some GPS positions show you as on dry land when you look at a
chart and a "cocked hat" sextant fix a mile on a side is doing really
good, i.e., you are somewhere inside a half a square mile area.

You can't use celestial navigation to stay in the middle of a narrow
channel because you can't take shots and work the calculations fast
enough, even with a calculator.

The original poster asked " Should I learn celestial navigation before
doing circumnavigation ?" and to me the answer is a resounding NO!

If you want to learn an archaic skill such as sword fighting, shooting
the long bow, or shooting stars then more power to you but the ability
to do celestial navigation is not a necessary skill in today's world.

In closing let me say that I learned celestial navigation from a Lt.
Colonel, the Lead Navigator in a SAC B-52 squadron and used to carry a
sextant, H.O. tables and expensive watch and all that, but that was
fifty years ago. Things have changed.



Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Tue, 18 Sep 2007 01:28:53 -0000, otnmbrd
wrote:

Jere Lull wrote in news:2007091720575416807-
jerelull@maccom:

On 2007-09-16 16:36:13 -0400, roger said:

Why not rise above the crowd and learn celestial navigation. It is not
an obsolete skill and people respect those that know how to do it even
if they won't admit it.

Didn't Annapolis stop requiring celestial navigation a year or two back?


EG Annapolis is Navy..... not professional mariners.....nuff said


I have a good friend who is both a university trained Marine Engineer
and a licensed ships officer (2nd engineer). His primary work is being
a project manager on VLCC, modifications and repairs but between
projects sometimes sails as second engineer on VLCC's or container
ships.

During the last discussion of sextants I happened to run into him in
Singapore and asked him if modern shipping still used celestial
navigation. He told me that on some ships junior officers still took
noon sights but only because the Captain felt it was a useful skill
for a ship's officer. Other ships didn't have a sextant aboard.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

wrote in news:d26ve3lofos8h97d29tseulhljlqskidna@
4ax.com:

Things have changed.

I should say....click where you want to go and let The Cap'n figure out
how to steer it in the laptop...(c;

Ours is on wifi....Just plug into 12V anywhere on the boat.

By the way, I do have a very expensive Japanese sextant in a beautiful
storage box made of some fine wood, the HO tables, navigation books, etc.
I learned from a master chief quartermaster, USN, on the open bridge of
the USS Everglades (AD-24) from a man who'd been doing it for 35 years.
With the Navy's nice sextant, we could match the LORAN fix within about
400 yards, given enough time and great weather.

Sure wish we'd had GPS in the 60's....

Larry
--

During the last discussion of sextants I happened to run into him in
Singapore and asked him if modern shipping still used celestial
navigation. He told me that on some ships junior officers still took
noon sights but only because the Captain felt it was a useful skill
for a ship's officer. Other ships didn't have a sextant aboard.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)


The days of watching some relieving Mate come aboard with his sextant as
part of his gear, are over. However, a ship sextant and the pubs to use it
are still standard gear onboard.
Once again, it is not necessary to learn celestial for someone doing
offshore cruising, BUT, it is STILL a good safety practice to have the gear
(no matter how cheap) and the minimal pubs to make use of it in an
emergency