Who Still Practices Celestial Navigation ?

[lolarose]

Originally Posted by Eric.

I think you must have missed the part where I said it was WEST not east. But thanks for the pedantic response.

Eric

.....from your web site before you changed it.

5.This result is your Longitude. Note that it is East because your local apparent noon (LAN) is later than noon at MP.


if your local noon is later than greenwich noon it is always W (14:45 W, 9:45 E)

and EoT for 27/11/2004 was 12min 34sec

but does not matter. sorry if i upset you

regardin nautical almanac i am using this web site.

Download

[Eric.]

Originally Posted by foolishsailor

Personally i like the cn and dr just cause every once in awhile i can turn everything off on passage and pretend i am sailing during the golden age when it was harder and there were less boats and less marinas etc

Edit: i did 4 landfalls solely with cn and dr; puerto corinto nicuaragua, puntarenas and golfito bay costa rica, and panama canal

Do you still use it or was that back in the '90s? The only people I've found that have any real interest/experience with it are people who sailed pre-GPS or when GPS's were over $1K.

I really wanted to make a portable Nautical Almanac (multi-platform) and I've got something that is quite good and includes a star database. But as I started working on generating the star charts, planet visibility diagrams, and other supporting material I realized the work involved was going to be too involved to just give it away. So I started asking around and no one was very interested anyway even for free! It was a great learning experience.

[Eric.]

lolarose, Thanks again for catching that it was West and not East as I mentioned in my reply to you but you might have missed it. It was quite an obvious error when I re-read the example. I'm glad you took enough interest to even look at it, most people don't.

Originally Posted by lolarose

and EoT for 27/11/2004 was 12min 34sec

As I'm sure you know EoT is always changing. I don't know at what time
NavSoft computed their EoT for that day. Many Almanac's choose either 0:00 or 12:00 (or both). I can tell you that the EoT in my tables correspond to my Reed's Almanac (UNSO approved) and is computed at the time of MP for the Sun. I am using an approximation and there are several accepted ways to approximate the two effects that create the EoT errors.

[Cpt Pat]

Originally Posted by Don Lucas

never leaned and don't see any reason to do so

this isn't the 1600s anymore

maybe if a sextant was like $50 I would learn but as long as a back up GPS is less than a sextant why bother other than to say you are all salty

Suggested reading:

U.S. Department of Transportation. Office of the Secretary ... Volpe Report on GPS Vulnerability
http://www.fas.org/spp/military/prog...t/gpstrans.pdf

Current Projects: GPS Spoofing - Vulnerability Assessment Team - Argonne National Laboratory

Maritime Jamming Trial Shows GPS Vulnerabilities | GPS World

Cornell University Researchers Demonstrated GPS Vulnerability with Spoofing Activities « My Digital Life

Captured U.S. stealthy drone was hijacked exploiting GPS vulnerability. « The Aviationist

There's a reason why the US Navy still takes sightings with a sextant.

We are approaching the period of maximum solar sunspot activity, which follows an 11 year cycle. If the sun tosses us a coronal mass ejection like the Carrington Event that occurred before, we could experience an extended period of GPS disruption: A Super Solar Flare - NASA Science

[foolishsailor]

Originally Posted by Eric.

Do you still use it or was that back in the '90s? The only people I've found that have any real interest/experience with it are people who sailed pre-GPS or when GPS's were over $1K..

I do still use it but as i travel with two small children finding spare energy to offer somethng "nonessential" is limited. 93 was the last time i did a passage of any substance without electronics. I do at least one set of star shots every passage, weather permitting, but mostly break it out for sun shots or lazy noon sites.

I would fit the above demographic you mention as well...

[lolarose]

Originally Posted by Eric.

lolarose, Thanks again for catching that it was West and not East as I mentioned in my reply to you but you might have missed it. It was quite an obvious error when I re-read the example. I'm glad you took enough interest to even look at it, most people don't.


As I'm sure you know EoT is always changing. I don't know at what time
NavSoft computed their EoT for that day. Many Almanac's choose either 0:00 or 12:00 (or both). I can tell you that the EoT in my tables correspond to my Reed's Almanac (UNSO approved) and is computed at the time of MP for the Sun. I am using an approximation and there are several accepted ways to approximate the two effects that create the EoT errors.

eric, can you tell mi which almanac you have bin using at that ime. i have 2004 almanac and my latitude is N 34°55.0'.

for example. my SD is 16'.2 and alt.corr. 1'.5, dec is 21°15.5'

and this is your calculation ......the latitude is N 35°06.3'.

thanks

[C4 King Cobra]

Geoduck, My bad, spelling britework, The art of maintaining the apperance of your vessel. Try doing it better than doing nothing. IMHO

[Viilettaja]

My 70 year old dad did this CN course (7 hours in the final test) and passed it. He cant even get into the boat anymore. There is the respect of seaman ship! People who rely on GPS and have no clue on navigation are asking for it. Sea is to be respected and knowledge in this mater is respect.

As my brother is a coast guard he can tell you some sad stories about GPS navigation when it fails. Hope its not dark or foggy when it happens.

[C4 King Cobra]

Originally Posted by Viilettaja

My 70 year old dad did this CN course (7 hours in the final test) and passed it. He cant even get into the boat anymore. There is the respect of seaman ship! People who rely on GPS and have no clue on navigation are asking for it. Sea is to be respected and knowledge in this mater is respect.

As my brother is a coast guard he can tell you some sad stories about GPS navigation when it fails. Hope its not dark or foggy when it happens.

Amen to that!

[sidmon]

Originally Posted by Viilettaja

People who rely on GPS and have no clue on navigation are asking for it. Sea is to be respected and knowledge in this mater is respect.

As my brother is a coast guard he can tell you some sad stories about GPS navigation when it fails. Hope its not dark or foggy when it happens.

Be careful. There are those who lurk about CF who will go out of their way to vilify you for such heretical thoughts...The mantra is that you are a fool to continue with such archaic trivia. Get with program, hit the on button and fire up your multi-thousand dollar integrated electronic suite!!! The equipment has all this going to sea in little boats stuff solved now. And don't forget to sport that too tight speedo while slurping down those salty margaritas!

Lin Pardey said it best earlier in the thread, deriving your position is all part of the experience, and then seeing that landfall burn away any doubts you may have carried for days, or even weeks, about just exactly where on this big world you really are. As they say, that experience is priceless.

Now, let me be quick to say that I am the proud owner of a chart plotter (NMEA0183 integrated BTW). The above was not a call to get rid of all electronics off the boat! Just sayin' it again: No matter the tools you use, ALWAYS stay connected to the basics.

If that box starts spitting and hissing like a rabid cat before suddenly going dark, is the DR plot in your head?

In that regard Ms. Pardey also buttresses a point I've been trying to make here at CF for a couple of months now:

Originally Posted by Lin Pardey

Did the GPS make us feel safer? In a small way it did the opposite. Now we had to remind ourselves that the ease of finding our position could lure us into cutting corners as we passed headlands or reefs, or entering new anchorages at night rather than heaving to to wait for daylight.

Those Sirens sing a right subtle tune...

But anyway, just got some grist for the Kindle by picking Joshua Slocum's "Sailing Alone Around The World"

At the end of chapter XI, he describes his navigation out to the Marquesas:

I sailed with a free wind day after day, marking the position of my ship on the chart with considerable precision;but his was down by intuition, I think, more than by slavish calculations. For one whole month my vessel held her course true; I had not, the while, so much as a light in the binnacle. The Southern Cross I saw every night abeam. The sun every morning came up astern, every evening it went down ahead. I wished for no other compass to guide me, for these were true.

Read it all. At less than 3 bucks its a good deal if you are looking for something to put on the Kindle...

[Viilettaja]

Originally Posted by sidmon

Now, let me be quick to say that I am the proud owner of a chart plotter (NMEA0183 integrated BTW). The above was not a call to get rid of all electronics off the boat! Just sayin' it again: No matter the tools you use, ALWAYS stay connected to the basics.

If that box starts spitting and hissing like a rabid cat before suddenly going dark, is the DR plot in your head?

At the end of chapter XI, he describes his navigation out to the Marquesas:

I sailed with a free wind day after day, marking the position of my ship on the chart with considerable precision;but his was down by intuition, I think, more than by slavish calculations. For one whole month my vessel held her course true; I had not, the while, so much as a light in the binnacle. The Southern Cross I saw every night abeam. The sun every morning came up astern, every evening it went down ahead. I wished for no other compass to guide me, for these were true.

Read it all. At less than 3 bucks its a good deal if you are looking for something to put on the Kindle...

You are correct. I also have GPS which I turn on if I suspect some markings have floated a way in the sea. It is nice tool to give you comfirmation in these situations. I think the worst thing people do now is that they dont even have chart in the boat.

Tell you the truth 8 hour day sailing would be little boring without navigation

[gjordan]

Just this afternoon I found my old Celestial book, after 20 years of storage. I had previously posted that it was titled (Ten Easy Steps to Celestial Navigation). That was the sub title. The actual title was SELF-TAUGHT NAVIGATION, by Robert Kittredge. It makes CF silly simple. It taught you everything you needed to do Sun, Stars, Moon, and planets in a 1/4 inch thick book. There was no BS and nothing that wasnt needed. It has been almost 40 years since I learned and 20 years since I have used CF, so I will have to dust off my brain cells and get to it.____Grant.

[AllezCat]

I bought a new sextant, and a few books. Intend to teach myself (like everything else) when I really need to.
Used one in the past for coastal (horizontal) - reckon its worth it just for that use.
But, horizontal is probably about 2% of its potential/knowledge required for celestial.
I am also planning to get captain's license, and become proficient with SSB - lot of dust on these books..

[gjordan]

My brain must have been really dusty when I put CF in my last post, instead of CN. In the box that I found my books in, I also found an old video by William F Buckly that was supposed to teach you CN. I remember it as the best sleeping aid a sailor could have.______Grant.

[deckofficer]

The "new and improved" version of this thread is here http://www.cruisersforum.com/forums/...oll-76732.html if anyone is interested.