The New and Improved Celestial Navigation Poll

[susanna reiter]

Gosh.. I am in the majority on this poll ( procrastination is my long suit)...in the mean time..I will continue to use the "calabash"....but the chop on the water always makes that a bit difficult...ROFL

[Geoduck]

Originally Posted by s/v Jedi

p.s. For all of those that buy old Russian or Iranian sextants made from brass in wooden boxes etc. : for $0.99 you can just buy the iPhone app and be done with it



ciao!
Nick.

Ok Nick - I give up! Where is it? I've looked everywhere in the Nav catagories for I-tunes App store - can't find it!

[s/v Jedi]

Originally Posted by Geoduck

Ok Nick - I give up! Where is it? I've looked everywhere in the Nav catagories for I-tunes App store - can't find it!

Turn on iPhone, go to app store, select search, type sextant, tap go....

First hit is the app.

cheers,
Nick.

[barnakiel]

I think a plastic sextant is a nice thing for training and may be used as an emergency or backup equipment. But anybody who does want to use their sextant for navigation may consider going right for a simple metal one: they are not much more expensive, they are more accurate and they offer better mechanics&optics.

b.

[s/v Jedi]

Originally Posted by barnakiel

I think a plastic sextant is a nice thing for training and may be used as an emergency or backup equipment. But anybody who does want to use their sextant for navigation may consider going right for a simple metal one: they are not much more expensive, they are more accurate and they offer better mechanics&optics.

b.

For emergency survival mode?

cheers,
Nick.

[rubyjean]

I shoot my sextant quite often while underway. I'm 64 yrs old now and try to keep my brain active w/ math to keep the grey matter from turning black..I too use the GPS daily and have a plotter. But we all need something to stay busy. Alway's carry paper charts on board and use them. I have found serveral errors w/ chart plotter info.. It's just peace of mind for me & the wife..Michael..

[Geoduck]

Originally Posted by s/v Jedi

Turn on iPhone, go to app store, select search, type sextant, tap go....

First hit is the app.

cheers,
Nick.

Now why didn't I think of that?

[moira]

Originally Posted by barnakiel

I think a plastic sextant is a nice thing for training and may be used as an emergency or backup equipment. But anybody who does want to use their sextant for navigation may consider going right for a simple metal one: they are not much more expensive, they are more accurate and they offer better mechanics&optics.

b.

How accurate does a sextant have to be? Any sextant, the plastic ones included are more accurate than the human using it. A high dollar insturment may give you a warm and fuzzy feeling but it will not insure you that you will get a better LOP from an observation.

[Astrid]

How accurate does a sextant have to be? Any sextant, the plastic ones included are more accurate than the human using it. A high dollar insturment may give you a warm and fuzzy feeling but it will not insure you that you will get a better LOP from an observation.

First let me say that a plastic sextant such as a Davis Mk 15 is sufficiently accurate for practical navigation and is capable of reliably getting a good operator within 4 to 10 miles of true position. I would certainly advocate one for a beginner learning the ropes; if one eventually decides it is too much trouble and prefers instead to use electronic navigational aids instead, then one won't be out a whole lot of money. A top of the line metal sextant on the other hand, can get you within a mile or less if you are careful. A Davis would be perfectly adequate for getting you to a destination provided the destination is relatively large and easily spotted. If your destination is a small, low-lying island like Howland or Gardner, a good top of the line sextant such as my C.Plath or Freiberger will put you within visual sighting distance; a plastic sextant might if you are both good and lucky, put you within visual range, but most likely will not.

The following has some interesting insights into using a plastic sextant:

http://www.starpath.com/online/celestial/plastic.pdf

[deckofficer]

Originally Posted by Astrid

First let me say that a plastic sextant such as a Davis Mk 15 is sufficiently accurate for practical navigation and is capable of reliably getting a good operator within 4 to 10 miles of true position. I would certainly advocate one for a beginner learning the ropes; if one eventually decides it is too much trouble and prefers instead to use electronic navigational aids instead, then one won't be out a whole lot of money. A top of the line metal sextant on the other hand, can get you within a mile or less if you are careful. A Davis would be perfectly adequate for getting you to a destination provided the destination is relatively large and easily spotted. If your destination is a small, low-lying island like Howland or Gardner, a good top of the line sextant such as my C.Plath or Freiberger will put you within visual sighting distance; a plastic sextant might if you are both good and lucky, put you within visual range, but most likely will not.

The following has some interesting insights into using a plastic sextant:

http://www.starpath.com/online/celestial/plastic.pdf

Now your speaking my language. I'll bet you pin wheel your LOPs on a small scale chart, don't you?

[moira]

Originally Posted by Astrid

First let me say that a plastic sextant such as a Davis Mk 15 is sufficiently accurate for practical navigation and is capable of reliably getting a good operator within 4 to 10 miles of true position. I would certainly advocate one for a beginner learning the ropes; if one eventually decides it is too much trouble and prefers instead to use electronic navigational aids instead, then one won't be out a whole lot of money. A top of the line metal sextant on the other hand, can get you within a mile or less if you are careful. A Davis would be perfectly adequate for getting you to a destination provided the destination is relatively large and easily spotted. If your destination is a small, low-lying island like Howland or Gardner, a good top of the line sextant such as my C.Plath or Freiberger will put you within visual sighting distance; a plastic sextant might if you are both good and lucky, put you within visual range, but most likely will not.

The following has some interesting insights into using a plastic sextant:

http://www.starpath.com/online/celestial/plastic.pdf

The part about the food fight covinced me that I had reached the end of this thread.

[barnakiel]

Originally Posted by moira

How accurate does a sextant have to be? Any sextant, the plastic ones included are more accurate than the human using it. A high dollar insturment may give you a warm and fuzzy feeling but it will not insure you that you will get a better LOP from an observation.

I am afraid, half of the time, you may be wrong. Think about it this way:

- there will be some observation error,
- there will be some data/calculation error,
- there will be some instrument error,
- etc.

Now, if we assume these small errors will balance out, then your attitude is correct. But how likely is this, and are we going to bet our security on it?

Cheers,
barnie
SMALL PRINT: SOMEHOW ERRORS TEND TO SUM UP at least half of the time ...

[barnakiel]

Originally Posted by s/v Jedi

For emergency survival mode?

cheers,
Nick.

I think a position from a plastic sextant is better than no position (well, read it: better than a DR after a 1000 mile+ run.

I think inexpensive metal sextants are worth the small extra we pay for the metal.

Having used a cheap metal sextant (for navigation) and a plastic sextant (to see the difference) I would pick up the metal one for navigation.

b.

[alacrity]

Has any one ever used easynav software. You can enter sights cog sog and it acts like a plotter. Plus you wouldnt need all the books. I have just downloaded the free trial once I get it figured out I'll tell you how I feel about it. Hopefully someone has tried it.

[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..(cpy&pasted from other cn thread).
Is a calculator, or software program worth it - or anathema to the whole idea? And how many books - almanacs and sight reduction tables do you need?
thx