What got you interested in Celestial Navigation?

[Ken Gebhart, Jr.]

I think it would be very interesting to know how our members got started in celestial navigation. Please take a moment and share with us your story.

[manxcat]

Dear Ken,
Reading about Amelia Earhart and Fred Noonan got me interested in celestial navigation. I am very intrigued by celestial navi; unfortunately, I am a very poor when it comes to math. All I know about trigonometry is that my older, much smarter sister hated trig because it was so-o-o-o difficult for her. I understand there are computer programs that do most of the math for you, as well as the other ‘scut’ work? I saw the classified add on your site, advertising a bubble sextant… can these be used at sea; or, on land? Can some marine type sextants be used when the horizon in not visible [a pan of mercury?]

Thanks & Have a Nice Day,
Joseph

[Ken Gebhart, Jr.]

Hi Joseph,

Don’t let the math scare you. It looks difficult because it is unfamiliar to you. Once you’ve reduced a few sights the “lightbulb” will go off. There are numerous worksheets, calculators, apps and computer programs available to help you with “the math” .

Bubble sextants can be used on land, sea or air.

You need some type of horizon, whether it is natural or artificial to take a sight. Artificial horizons come in a variety of flavors. You can use a pan of oil [not mercury!]. Davis Instruments manufactures an artificial horizon which can be used with any type of sextant. Celestaire manufactures a Practice Bubble Horizon which can be used on most modern marine sextants and Cassens & Plath manufactures a Professional Bubble Horizon which can also be used on most modern marine sextants.

[Steven Carleton]

Ken:

When I was a kid, I read several novels by the Australian author Neville Shute about his experience as a bomber navigator in WWII. It seemed like a miracle to me that they could fly above the cloud cover in the dead of night and determine a reasonably accurate position with a 3 lb. hand-held device and a book of tables. Then in 1976 I found a functional air sextant and a Rude star finder at a camera store – the owners didn’t know what they were, and let me have it all for $15.00. I still use them, today. The hook was set!

Best,

Steve

[JDavHouston]

I got interested while reading a book on the history of aviation, and realized that Air Navigation via celestial and ‘traditional’ radio means was a dying art, so I decided to learn and practice these skills so that they’ll be maintained.

[mcaminos]

I have been sailing for over 20 years now, and flying for about 10 years, so I always had to use charts to create navigation and flight plans. Although you can create a either a marine or flight plan with the computer, during the instruction and license test you have to demonstrate you can do it manually.

Celestial navigation came naturally after that, in theory as a back up plan (in particular in a sailboat), but more for fun and also to give my amateur astronomy hobby a practical application.

[manxcat]

To: Mcaminos From: manxcat
Navigators such as Gary LaPook and William Polhemus have used 1937 astronautical almanacs to recreate what Fred Nonoon’s ‘pre-flight plan’ may have looked like for the Amelia Earhart World Flight. The late William Polhemus actually flew, as navigator, for the first Commemorative A.E. World Flight in 1967. They used a restored Lockheed Electra for the entire flight around the world, at or near the equator. I believe Polhemus took astral sights with a bubble octant / sextant every half-hour along with wind direction & speed throughout the night before siting the original A.E. destination of Howland Island–which, of course, A. E. and Nonoon missed in 1937. The principle pilot for the 1967 Commemorative was Ann H. Pellegreno. The entire 1967 flight crew were exceptionally qualified for this flight. William Polhemus was a past president of the Institute of Navigation and gave a speech regarding his navigation during the ’67 flight, along with his opinions about where Nonoon and Earhart may have messed up on what was likely the final leg of their abortive flight. (HINT: Amelia may have lost some of her famous composure in a very tight situation.)
Gary LaPook is a pilot who owns several bubble octants / sextants and is a celnav buff with a lot of experience… he is the kind of celnav hobbyist that your wrote about in your recent post. He also has made a detailed study of the A.E. 1937 flight that you can read Online at frenoonon site

As Amelia Earhart signed off on her letters:
Cheers
–Joseph

[AlStewartJM]

Hello all!

Happy to be here, I regularly take practice sights from the beach near the old pirate city of Port Royal, Jamaica.

I grew up sailing with my dad here, working foredeck in the 1980’s racing a J-30 then on an Oyster Lightwave 395 in the 1990’s. I was also serving as a reserve officer in our Coast Guard, and developed an interest in celestial navigation in the 1990’s, taking my first practice sights (Evening Stars) with my Davis Mark 20 on a patrol boat in the Gulf of Mexico!

While I grew up in an environment of DR in small boats, through early SatNav to fixing by gyro and radar ranges, etc. I was able to see the introduction and gradual shift to wholesale reliance on electronic systems, and grew concerned that our current navigators are not practicing traditional methods.

After retiring from reserve service in 2012, I was encouraged by my former “boss” to develop an “Astro Club” to preserve the art and have been working on this small project since 2019. In addition to the Davis sextant, I have a 1975 International Nautical “Tamaya-Like” and a 1939 Heath Bell-Frame all in working condition, and have been sharing the art with several persons here.

I look forward to learning and sharing with you all here, and am also active as a moderator on Facebook group “Practical Celestial Navigation”.

[micke]

When I was 9 years of age in 1972 my dad got an Ebbco plastic sextant, a Nautical Almanac and went to an evening class to learn this. Exactly why he did this is a bit of a mystery though. I think it was just general curiosity as our boat is in a lake and not in the Atlantic. Tabular data has always had an impression on my nerdier side so I was hooked. In high school I found formulae for the sun’s orbit and programmed my ZX81 and later ZX Spectrum with them.

I remember trying to get fixes by the sun but was always more than a nautical mile away. Recently there was Freiberger Trommelsextant on an auction site and with an artifical horizon, or in the boat, I now get MUCH better fixes, definitely within 1 nautical mile and sometimes even spot on.

So, that’s the what. The why is partly because of a mathematical fascination in the subject and partly to keep the ancient old methods alive.

The Freiberger’s micrometer was stuck on delivery so it was a nice mechanical challenge to get it going again. I have repaired cameras and shutters as a hobby so I had the tools for that.

[manxcat]

To: Micke,
How do you perform the math on your sightings? (or do you?) Handheld scientific calculator or laptop, other?
From reading and posting on this site, I’ve learned that you have to be very handy with making repairs and adjustments on outdated equipment (e.g. artificial horizon sextants et cetera.

Have a Nice Day,
Joseph

[micke]

Hello Joseph,

for now I have made a program for my HP-15c that gives med Hc and Az of the Sun. It’s nothing fancy and uses only Kepler (ie no planetary perturbations and such). Still the results conforms very well with the Nautical Almanac, usually within 1 minute-of-arc.

I do however have an old Ho214 which I intend to use for the fun of it as I can get GHA and δ from the same program. And also Ho-249 Sight Reduction Tables for epoch 1965:)

Regarding the sextant, this https://jabcam.wordpress.com is a website of mine where I write about old cameras – and take them apart. Sometimes even repair them… So when the sextant was stuck I was prepared for that.

I use a Davis artificial horizon for sights in the garden.

Do you take actual sights?

Cheers
Micke

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