I'm really surprised to see an instruction about sextant now. It reminds me of my celestian navigation I took at school in the early 70's and our long navigations when we used celestial navigation extensively until 20 + years ago … and then we became stupidly lazy. There is nothing more satisfying to make a right course thanks to celestial navigation, there is no more satisfying thing to know where you are relative to the land / continents and to the celestial bodies… I do miss that a lot (along with the rest of sailing of course…).
@Lelz Rofl Dude ! You made the best response in YT since a very long time. Yes it is 5 000% more interesting than GPS and more … Cheers, Happy New Year and best of luck !…
My father was a master mariner/marine surveyor in the early '70s. I am only now at the age of 64 learning to use this instrument in spite of his eagerness to teach me because in those days motor cycles, horses and girls were far more important. It does give one peace of mind.
Outstanding series Chris. I did a tour on the carrier Carl Vinson CVN-70 in the 1990's. The navigator did his sextant readings daily, morning, noon and evening. I asked him why he bothered since he had GPS etc. His reply was that if there was a war (nuclear), GPS and all of that stuff would be gone and he would be back to navigating with the sextant. Convinced me to learn this skill. Glad I did!
The Communist Chinese have been frequently JAMMING all GPS reception over vast areas of the south China sea and South Pacific ocean! And we're not even at war with these bastards!
Excellent teaching video! Your presentation style is outstanding, the use of video close ups on the micrometer, the use of the laser pointer, and the thought the glass views are all very well done. I wish I had seen this video 26 years ago when I was learning how to use my sextant before a voyage. Your video clearly explains things. Fair winds sailor!
Dude, this is the third video about the sextant I've seen, and it blows the other two to bits. It's some of the same material, but presented in a way that a complete novice (me) understands every concept presented. You're the rare combination of a subject master and an effective teacher -- well done!
Great video! I've never understood how it was possible to measure such angles to such high resolution while sitting or standing on a moving object. Obvious when you know how. Thank-you!
Hi Chris! I very much like the smooth and veracity of your material. I am in the process of getting my first sextant and I hope some day I could shoot at the stars and put in practice what I have learned. Thank you for your kindness and for sharing your knowledge with others. May the Lord who created the heavens and know all the stars by its own name keep you safe out in the ocean by having always a heavenly body over your vessel.
Nice video. I am going to to learn this. It got me thinking how the sentiment these days is that we've left the entire past in the dust with the computer age. I can rarely get someone under 35 or so to be interested in anything not "techy". But can you imagine the minds the developed a technology like this. If I understand correctly it is accurate to within 1nm. The first sextant dates to around 1759. what is that, 264 years? I find that just amazing. No batteries or connection required. A beautiful, to me, tool and a book. And a brain.
Several years ago while my wife and I were taking a cruise, we had the opportunity to join a group tour of the bridge. After the Captain finished describing the advanced satellite navigation systems and sophisticated displays, one of our group (sarcastically in my opinion) asked where they kept the sextant. An officer walked over to one of the desks, opened a drawer and pulled out, with a subtle smirk, a sextant and paper map . He never asked another question. It was great to see.
Being a new Merchant Mariner/Seafarer I am very interested in learning the old school navigation methods and tools. This is very interesting and informative indeed! Thanks for sharing!! 🇺🇸⚓️🌊⛴
A sextant (and any protractor, but with varying degrees of accuracy) can also be used to do a lot of other nifty things. You could, for example, measure the angle between two or more landmarks (usually on the coast), trace the lines/angles on the chart, and triangulate your position.
Excellent explanation of reading the Vernier Will. This is something I've never felt comfortable with until this point and that explanation made it crystal clear very well done video
Hi Chris, We are a homeschoolin' family and just read "Carry On Mr. Bowditch" by Jean Lee Latham. I wanted to learn more about reading a sexton and found your YT. You are a modern day Nathaniel Bowditch! It is children's literature but an excellent book to read-consider it. Thank you.
when I was in the Navy we were transiting from the Panama Canal to San Diego. We lost our Loran and couldn't get a good idea where we were. We surfaced and our Navigator went to the bridge shot the stars and got our position. Once they fixed our navigation systems it was determined he was correct within 100 yards. Not bad!
If you found this interesting, you can buy a very basic sextant for less than $50: the Davis Mk 3, which is a plastic version of the WWII lifeboat sextant. There are also patterns available on the Web for making your own sextant out of wood or cardboard. (Probably for using a 3D printer, too, but I haven't researched that.) It's fun to actually put the skills shown to use; better than just reading/watching about them.
Thank you most sincerely, sir! A fellow boater and friend of mine recently gifted me with a sextant! (I was, like, "A 'sex' what?!)... So, now, very cool! My eternal appreciation for your excellent lesson. Godspeed!
Chris, I have to say that I have reviewed a lot of videos about Celestial Navigation and yours by far are the most comprehensive ones out there. Your teaching methods and video techniques have exceeded my expectations. If you have a moment I would like your thoughts on a question I have about the possibility of eye injury risks involved with using a Sextant. Do you think the constant use of taking shots with the proper shades in place could cause short term or longer term eye injuries. Even with all of the shades in place I am not sure what damage is being done to the eyes looking at the sun on a continual basis. I would like to purchase a Davis Mark 25 but the only thing holding me back are the risks associated with possible eye injury. Thank you very much for your videos and time.
Hi Flying, sure thing - the sextant shades are of similar quality to what welders or astronomers use for their work. If you use the appropriate amount of shades you should have no problem. Thanks!
@@NavigationTraining Chris. Thank you very much for the information. I greatly appreciate it. I have learned so much from your videos and the information on your website. Thank you so much for sharing your knowledge and experience with us.
Hi Mark, I know many sextants have removable telescopes (mine included) - however most are not very powerful, only a few times magnification. As far as spyglass with sextant attachment, I can't recall seeing anything like that, but that doesn't mean it doesn't exist!
Third video I've watched on the sextant so far and the best. I like how it gets to the basic idea of what you do and what you see etc. I knew nothing about it 10 minutes ago now I got a rough idea. I wanted to research after seeing Robert Redford use one in All is Lost. Next thing I wanna look up is, how do you take those measurements and apply them to a map? I guess there is a video on that also. I will look.
I was curious how this is done. This is the 3rd and easiest, although not easy, instruction I’ve watched. It is not clear to me after you take this measurement - how do you know where you are?
Hi Chris, Thanks so much for your video's I have been trying to learn Celestial Navagation on my own for some time using a Davis Mark 25. One question....you reference "notes below" at the end of most of your videos. How does one access those notes? Thanks again, you make this seem more understandable than most.
Thanks Pat, glad to hear it! If you look just a few lines up from this comment, to the "Published on April 5, 2013" section, click on the "show more" button and it should give you all the references. Good luck! - Chris
Nice intro and well spoken for a beginner like myself interested in the likes of David Thompson explorer map maker. Seems though, it would be well to do with having a lanyard for this device especially around water.
AlanBoatyman Hi Alan, I do recommend it, however I would say that pretty much any sextant is good enough for the job...if you buy new, great, but if you buy used, just be sure to check the motion of the arm, and also that you can see through the telescope clearly. Plastic sextants are perfectly good as well, especially for starting out...but if you are looking for a lifelong partner, the IIIB is a good investment - good luck!
Hi Cole, this is done to make sure that you aren't looking at the sun in a cockeyed position. It helps make sure that everything is lined up correctly. For instance if you hold the sextant slightly tilted, the sun appears to rise or set. Swinging just makes sure it is as accurate as possible. Thanks!
how Automatic astrotrackers such as, MD-1 Automatic Astro navigation system, work? how it know about which star it measuring (without image processing)?
Hello! Usually in rough weather your first concern is bracing yourself somewhere. Then, I usually take the average altitude measurement when I can actually see the horizon over the waves. It is beneficial to take a bunch of measurements and average them for height and time. Thanks!
Hello Prem, I use the altitude intercept method at all times of the day to find lines of position. You need a chronometer (time) to use the method to maximum accuracy. At noon, you don't need the chronometer to calculate a line of latitude from the sun. Hope that helps!
Hi Michael, this is an Astra IIIB, for about $500 used. Don't hesitate to use the plastic Davis Sextants, they are very good as well. If I were starting, I would use a Davis to learn, and then if you truly like it, move up to a metal one. Even a used sextant can be refurbished...I have another video in the series regarding adjusting a sextant for error. Good luck!
I am new to this - one wonders whether there is a calculator or similar to give position once angle is found? There is a French computer sextant that seems much safer than looking at the sun through a telescope!
"StarPilot" sells a TI-89 with built in CelNav software. www.starpilotllc.com/ I highly recommend these android apps: "Celestial" by Navimatics play.google.com/store/apps/details?id=com.navimatics.app.celnav "Sight Reduction" by Navigational Algorithms play.google.com/store/apps/details?id=com.Sightreduction "Nautical Astronomy" by Navigational Algorithms play.google.com/store/apps/details?id=com.AstroNavigation "Nautical Almanac" by Navigational Algorithms play.google.com/store/apps/details?id=com.NauticalAlmanac Navigational Algorithms also makes some great free PC software. There are also fomulae in the "explanation" section of the Nautical Almanac which can be used with any calculator and/or spreadsheet/program capable of trig functions.
Hey ,Thanks for this great lead in primer video , I just bought a really nice plastic Dais Mark 25 version for 2 bucks at second hand place ..no manual though so her I am !! THank you
Hello Toni, Celestaire is the manufacturer and it is also available on Amazon, but don't feel like you have to start with a metal sextant, plastic ones are good too.
i didnt understand the part where you need to separate the sun into two parts, shouldnt you only lower the sun with the shades on to a lower limb on the horizon ?Thanks
Hi Whisperin - depends on your sextant. Usually even with the shades down you will see two sun images if you move the micrometer drum about 30 seconds of arc. In the video you can see exactly what it looks like through the lens, we put a camera right where your eye would go when using it. Some sextants called "whole horizon" have a different mirror set up.
Hi,Chris,best regards from Bulgaria,from a future Navigator. Great movies great knowledge,everything perfect!!! I would like to ask about the sextant you are using in those videos.What Celestaire model exactly it is?...as I am planning on buying one of these.Is it the Astra III with Trad mirror or the one with WH mirror? Love Celestial navigation. Thank you in advance ,take care. Rosen
Hi Rosen, thanks for writing. This particular sextant is the traditional split mirror. If you get a chance to use a whole horizon mirror, many people like them better. However anything will do the job. Good luck! - Chris
I do appreciate your answer, Chris. Once I bought it,I will send a photo !......can't wait. Thanks again for answering,and I wish 7 foot under the keel,and God Bless!
Though i wonder, you sextant isnt stable it lifted by human which is also rocking. How can you properly measure something which so much things in motion?
That is a good point Rombout, depending on the sea conditions, you sometimes need to average your height between the peaks and troughs of the waves. If you get a chance to look through one, it might clarify your point, for the most part if you assume you use a sextant to navigate on the open sea, an error of a mile or so isn't catastrophic. So a combination of knowing your height (or averaging it) and keeping yourself as steady as possible does the trick. Thanks!
Also as low as possible on the ship than, that means the least amount of motion or rocking. My father had one, but i havent touched that thing in 20 years orso.
Because the two mirrors on the sextant are consistently relative to each other without regard for the movement of the operator, it is actually much more stable than you would think. I can do deep knee bends while taking a shot and the horizon and sun do not jump around but stay right in view in a very stable manner as I screw them down to just touching.
Hi Chris, Alidades measure horizontal angles (parallel to the sea) and the sextant can do both horiztonal (if you hold it sideways) and vertical (if you hold it normally). You would use an alidade for taking bearings from objects to plot on a chart or maybe to do some celestial nav when the object is close to the horizon. Thanks!
Hello Mike, So the two shades are termed horizon shades (the lower ones) and index shades (the upper ones). You should feel free to remove the horizon shades when you get close to the horizon, but the index shades should remain in place. When using a "whole horizon" sextant, you can likewise remove the horizon shades, but you should keep the index shades in place. You can experiment with the shades a bit but stay safe! Thanks!
Can we get a video of all the basic requirements for calculating long/lat w/ a sextant, watch & nautical almanac? Is a calculator, protractor, ruller... graph sheets... needed? What else? I watched this video a few times & I don't quite understand exactly what you're doing. I'm sure it's good info, but it's just not clearly & thoroughly explained enough for me to grasp it. I saw you split the sun into 2. I think you aligned the top of the lower-sun w/ something. Heck, I really just can't tell what you did.
After watching a few more times, I see what you did. It's well explained enough. Lots covered very quickly. Another item one may need is a chart of the stars if the starcharts in the nautical almanac aren't good enough. There are brass sextants on ebay for < $20.00 I wonder if those would suffice. They're a bit small, & I'm not sure if they have lenses, but maybe one can war polarized sunglasses & use it.
ComandOr Zerxius I just looked over the $20 sextant on Ebay (BR4850B 4" Antiqued Sextant). It seems a bit small & lacks the fine-tuning device that yours had, but like you said, you don't need the seconds adjustments, so, do you think this would be adequate for measuring distance w/in 2 miles? How accurate do you suppose this might get you? 4 miles?
ComandOr Zerxius Hello, thanks for watching. I think the sextant you describe might be a little small to learn the fundamentals - I might suggest starting with a plastic Davis sextant, a used one should be fairly inexpensive. This video is part of a larger series of 11 Celestial Navigation videos which are all available on the channel. In order to present the maximum amount of information, we move very quickly, with the assumption that viewers will either pause the video or watch it a few times to accomplish the tasks. You can access all the rest of the videos on the navigation training channel (click under the video). Thanks again!
Vincent Becker Hi Vincent - there are many apps available - the one I used is called "triangle solver" but that is for plane triangles. Cruising World did an article www.cruisingworld.com/gear/theres-app about a few good boating apps, among them was EZsights for celestial navigation. I would look at a few reviews on the app stores and see what fits your needs best. Good luck!
I would say the Davis plastic sextants are a decent place to start. Here is a video describing the differences: ruclips.net/video/w2xAqww_X_U/видео.html
Celestial Navigation works because of spherical trigonometry. The angle taken from the sextant is input to a set of S.T. geometric equations that provide enough data to make your positional plot on the Chart. Some of this calculation can be seen on the videos over on my Channel
Thanks! This is easily the clearest, best presented, and most comprehensible explanation of how to use a sextant that I've ever seen...and at a total length of 7:51, well within the attention span of at least some RUclips viewers. :-)
Wow, I always thought using a sextant would be crazy complicated... You made this piece of metal that does magic into something logical that actually makes sense.
I'm really surprised to see an instruction about sextant now.
It reminds me of my celestian navigation I took at school in the early 70's and our long navigations when we used celestial navigation extensively until 20 + years ago … and then we became stupidly lazy.
There is nothing more satisfying to make a right course thanks to celestial navigation, there is no more satisfying thing to know where you are relative to the land / continents and to the celestial bodies…
I do miss that a lot (along with the rest of sailing of course…).
@Lelz Rofl Dude ! You made the best response in YT since a very long time.
Yes it is 5 000% more interesting than GPS and more …
Cheers, Happy New Year and best of luck !…
Lelz Rofl it’s wild how some of us are drawn to the sea... and then boring people like you are scared of water
@@stuarthiggerson5846 Your response is so predictable : who's boring ?
My father was a master mariner/marine surveyor in the early '70s. I am only now at the age of 64 learning to use this instrument in spite of his eagerness to teach me because in those days motor cycles, horses and girls were far more important. It does give one peace of mind.
Thumbs up.
man your way of explaining is so simple and up to point even a small child will grasp this easily ..much blessing to you mate ..
Outstanding series Chris. I did a tour on the carrier Carl Vinson CVN-70 in the 1990's. The navigator did his sextant readings daily, morning, noon and evening. I asked him why he bothered since he had GPS etc. His reply was that if there was a war (nuclear), GPS and all of that stuff would be gone and he would be back to navigating with the sextant. Convinced me to learn this skill. Glad I did!
Grandpa Jones
Better to have and not need then need and not have
The Communist Chinese have been frequently JAMMING all GPS reception over vast areas of the south China sea and South Pacific ocean!
And we're not even at war with these bastards!
@@pemaangya5830 Pema Angya
Grandpa Jones
Excellent teaching video! Your presentation style is outstanding, the use of video close ups on the micrometer, the use of the laser pointer, and the thought the glass views are all very well done. I wish I had seen this video 26 years ago when I was learning how to use my sextant before a voyage. Your video clearly explains things. Fair winds sailor!
Thanks for the kind words, all the best to you.
Dude, this is the third video about the sextant I've seen, and it blows the other two to bits.
It's some of the same material, but presented in a way that a complete novice (me) understands every concept presented.
You're the rare combination of a subject master and an effective teacher -- well done!
Thanks for the kind words Dave, enjoy your journey in celestial navigation!
Spot on mate
Great video! I've never understood how it was possible to measure such angles to such high resolution while sitting or standing on a moving object. Obvious when you know how. Thank-you!
Hi Chris! I very much like the smooth and veracity of your material. I am in the process of getting my first sextant and I hope some day I could shoot at the stars and put in practice what I have learned. Thank you for your kindness and for sharing your knowledge with others. May the Lord who created the heavens and know all the stars by its own name keep you safe out in the ocean by having always a heavenly body over your vessel.
I would like to thank you for the videos...I am sitting for Exams and I found them very helpful. All the best to you. Thank you again
Nice video. I am going to to learn this. It got me thinking how the sentiment these days is that we've left the entire past in the dust with the computer age. I can rarely get someone under 35 or so to be interested in anything not "techy". But can you imagine the minds the developed a technology like this. If I understand correctly it is accurate to within 1nm. The first sextant dates to around 1759. what is that, 264 years? I find that just amazing. No batteries or connection required. A beautiful, to me, tool and a book. And a brain.
An excellent video for learning the basics of a sextant. The setting gave me chills from great memories!
Glad you enjoyed it!
Several years ago while my wife and I were taking a cruise, we had the opportunity to join a group tour of the bridge. After the Captain finished describing the advanced satellite navigation systems and sophisticated displays, one of our group (sarcastically in my opinion) asked where they kept the sextant. An officer walked over to one of the desks, opened a drawer and pulled out, with a subtle smirk, a sextant and paper map .
He never asked another question. It was great to see.
Every Captain worth their salt would have one on their ship. Early Boeing 747 even had a sextant.
Being a new Merchant Mariner/Seafarer I am very interested in learning the old school navigation methods and tools. This is very interesting and informative indeed! Thanks for sharing!! 🇺🇸⚓️🌊⛴
Sir, I am a nautical science student and its for the first time I am understanding how to use sextant.. well taught sir
A sextant (and any protractor, but with varying degrees of accuracy) can also be used to do a lot of other nifty things. You could, for example, measure the angle between two or more landmarks (usually on the coast), trace the lines/angles on the chart, and triangulate your position.
Very Good Video for beginners to try and take hold of this most difficult subject, Thanks!
Thanks! Yep it's a Astra 3B. The flame job is custom :)
Excellent explanation of reading the Vernier Will. This is something I've never felt comfortable with until this point and that explanation made it crystal clear very well done video
Hi Chris, We are a homeschoolin' family and just read "Carry On Mr. Bowditch" by Jean Lee Latham. I wanted to learn more about reading a sexton and found your YT. You are a modern day Nathaniel Bowditch! It is children's literature but an excellent book to read-consider it. Thank you.
a well spoken young man and very good presentation
when I was in the Navy we were transiting from the Panama Canal to San Diego. We lost our Loran and couldn't get a good idea where we were. We surfaced and our Navigator went to the bridge shot the stars and got our position. Once they fixed our navigation systems it was determined he was correct within 100 yards. Not bad!
that was great...first time I've ever looked at a sextant..better late than never...
If you found this interesting, you can buy a very basic sextant for less than $50: the Davis Mk 3, which is a plastic version of the WWII lifeboat sextant. There are also patterns available on the Web for making your own sextant out of wood or cardboard. (Probably for using a 3D printer, too, but I haven't researched that.) It's fun to actually put the skills shown to use; better than just reading/watching about them.
You have produced excellent videos. It would be nice to add, how to calibrate a sextant, (the mirrors) before taking a shot.
Thanks for the feedback, I'll look at that topic for the next video series in the spring. Thanks again!
Excellent...clear and concise. Oh, to be in the summer sun again. It's the middle of February here in New Jersey.
Thanks for watching, I wish you good luck in your learning!
If you are shooting a sighting in the hood, do you hold the sextant sideways?
LOL. That's a crappy way to hold a pistol too.
Too funny...
lolz
Only a gangsta pirate would do navigate the high seas that way!
Of(f) course.
Just found these videos. You're a very good instructor - thank you for making these!
Just starting to learn and this video is excellent and so well presented.
Thank you extremely helpful and informative
Great tutorial and facinated to know how this device (sextant) works. (thanks)
Brilliant! I am just doing a course on Celestial Navigation, and this is a wonderful explanation on how to take the measurement. Thanks heaps :)
Great explanation. Thanks for all the links to resources.
Thank you most sincerely, sir! A fellow boater and friend of mine recently gifted me with a sextant! (I was, like, "A 'sex' what?!)...
So, now, very cool! My eternal appreciation for your excellent lesson.
Godspeed!
Excellent instruction. Thank you.
Nice learning with you, I have one and studying trigonometria
Chris, I have to say that I have reviewed a lot of videos about Celestial Navigation and yours by far are the most comprehensive ones out there. Your teaching methods and video techniques have exceeded my expectations. If you have a moment I would like your thoughts on a question I have about the possibility of eye injury risks involved with using a Sextant. Do you think the constant use of taking shots with the proper shades in place could cause short term or longer term eye injuries. Even with all of the shades in place I am not sure what damage is being done to the eyes looking at the sun on a continual basis. I would like to purchase a Davis Mark 25 but the only thing holding me back are the risks associated with possible eye injury. Thank you very much for your videos and time.
Hi Flying, sure thing - the sextant shades are of similar quality to what welders or astronomers use for their work. If you use the appropriate amount of shades you should have no problem. Thanks!
@@NavigationTraining Chris. Thank you very much for the information. I greatly appreciate it. I have learned so much from your videos and the information on your website. Thank you so much for sharing your knowledge and experience with us.
Hi Mark, I know many sextants have removable telescopes (mine included) - however most are not very powerful, only a few times magnification. As far as spyglass with sextant attachment, I can't recall seeing anything like that, but that doesn't mean it doesn't exist!
Excellent. Thanks. Always been interested in this. Thanks for explaining so well.
What kind of sextant is that ? I want one that is not a Davis plastic sextant. I like your style of explanation , thorough and fast
This is an Astra IIIB, thanks for watching!
Excellent tutorial and links. Keep up the good work!!!
What an awesome explanation. Keep pumping out these videos. Great job man.
Third video I've watched on the sextant so far and the best. I like how it gets to the basic idea of what you do and what you see etc. I knew nothing about it 10 minutes ago now I got a rough idea. I wanted to research after seeing Robert Redford use one in All is Lost. Next thing I wanna look up is, how do you take those measurements and apply them to a map? I guess there is a video on that also. I will look.
Chris has a video where he demonstrates the process of converting an observed altitude into an intercept.
700k views! Heartwarming to see I’m not alone ❤️❤️
Great videos Chris! Keep producing them, more detail though. I like the sailing video too, I'm stuck in the desert.
haha you are stuck in the desert and you keep seeing water everywhere no that's not water actually I meant mirage
I was curious how this is done. This is the 3rd and easiest, although not easy, instruction I’ve watched. It is not clear to me after you take this measurement - how do you know where you are?
Hi Chris, Thanks so much for your video's I have been trying to learn Celestial Navagation on my own for some time using a Davis Mark 25. One question....you reference "notes below" at the end of most of your videos. How does one access those notes? Thanks again, you make this seem more understandable than most.
Thanks Pat, glad to hear it! If you look just a few lines up from this comment, to the "Published on April 5, 2013" section, click on the "show more" button and it should give you all the references. Good luck! - Chris
celestial navigation is a class method
Thank you so much
Thanks a lot buddy, excellent......
gracias por tan buena explicación
Don't you need to do this at noon or is that old way of doing it?
Not a sailor, but thanks for clearing this up. Id always wondered.
Nice intro and well spoken for a beginner like myself interested in the likes of David Thompson explorer map maker. Seems though, it would be well to do with having a lanyard for this device especially around water.
Thanks Tramontane, Good advice - I often use a lanyard on the sextant, especially in rougher weather, but it depends on the conditions for me. Thanks!
Very good! Thank you.
Thanks
What brand is your sextant? Great vids by the way. Very helpful.
Hello, thanks! It is a Celestaire Astra IIIB, however the flame job is custom.
Aaaaah. Thanks!
Chris Nolan
Hi Chris - Do you recommend the Celestaire Astra IIIB as good reasonably priced sextant? I'd like to buy one and keep it forever!
AlanBoatyman Hi Alan, I do recommend it, however I would say that pretty much any sextant is good enough for the job...if you buy new, great, but if you buy used, just be sure to check the motion of the arm, and also that you can see through the telescope clearly. Plastic sextants are perfectly good as well, especially for starting out...but if you are looking for a lifelong partner, the IIIB is a good investment - good luck!
Great video! What is the reasoning for swinging the sextant and making sure the sun forms an arc with the bottom touching the horizon?
Hi Cole, this is done to make sure that you aren't looking at the sun in a cockeyed position. It helps make sure that everything is lined up correctly. For instance if you hold the sextant slightly tilted, the sun appears to rise or set. Swinging just makes sure it is as accurate as possible. Thanks!
how Automatic astrotrackers such as, MD-1 Automatic Astro navigation system, work? how it know about which star it measuring (without image processing)?
How would you use the sextant in less than ideal seas?
Hello! Usually in rough weather your first concern is bracing yourself somewhere. Then, I usually take the average altitude measurement when I can actually see the horizon over the waves. It is beneficial to take a bunch of measurements and average them for height and time. Thanks!
Could u explain y we prefer long by chron in morning and intercept in evening?
Hello Prem, I use the altitude intercept method at all times of the day to find lines of position. You need a chronometer (time) to use the method to maximum accuracy. At noon, you don't need the chronometer to calculate a line of latitude from the sun. Hope that helps!
Very useful review
What brand of Sexton are you using?
This is an Astra IIIB, but the flame job is mine!
@@NavigationTraining thank you. I appreciate you for this. I want to learn so much!
Dangit!
Now I have to go sextant shopping,
and get another boat.
loving this series. where are the notes though
Hi Jane, they are just below the video in the RUclips screen. They contain some links of interest. Thanks!
Hi Jane, if you click on the area in RUclips just below the video, there are a bunch of links and notes about the video. Good luck!
What is the brand and model of this sextant? How much for a decent one? How much for one comparable?
Hi Michael, this is an Astra IIIB, for about $500 used. Don't hesitate to use the plastic Davis Sextants, they are very good as well. If I were starting, I would use a Davis to learn, and then if you truly like it, move up to a metal one. Even a used sextant can be refurbished...I have another video in the series regarding adjusting a sextant for error. Good luck!
Thanks, great video
Where can I get a sextant like the one you are using in your video? I am enjoying your videos.
I am new to this - one wonders whether there is a calculator or similar to give position once angle is found? There is a French computer sextant that seems much safer than looking at the sun through a telescope!
"StarPilot" sells a TI-89 with built in CelNav software. www.starpilotllc.com/
I highly recommend these android apps:
"Celestial" by Navimatics play.google.com/store/apps/details?id=com.navimatics.app.celnav
"Sight Reduction" by Navigational Algorithms play.google.com/store/apps/details?id=com.Sightreduction
"Nautical Astronomy" by Navigational Algorithms play.google.com/store/apps/details?id=com.AstroNavigation
"Nautical Almanac" by Navigational Algorithms play.google.com/store/apps/details?id=com.NauticalAlmanac
Navigational Algorithms also makes some great free PC software. There are also fomulae in the "explanation" section of the Nautical Almanac which can be used with any calculator and/or spreadsheet/program capable of trig functions.
informative for maritime students
Hey ,Thanks for this great lead in primer video , I just bought a really nice plastic Dais Mark 25 version for 2 bucks at second hand place ..no manual though so her I am !!
THank you
Penic kimat ketli hai
Where you get sextant? All I find online are replicas..
Nicejob buddy
Hi my friend, where can to buy any sextant like this? Link store ? Thank you!
Hello Toni, Celestaire is the manufacturer and it is also available on Amazon, but don't feel like you have to start with a metal sextant, plastic ones are good too.
@@NavigationTraining thank you!
Take care!
i didnt understand the part where you need to separate the sun into two parts, shouldnt you only lower the sun with the shades on to a lower limb on the horizon ?Thanks
Hi Whisperin - depends on your sextant. Usually even with the shades down you will see two sun images if you move the micrometer drum about 30 seconds of arc. In the video you can see exactly what it looks like through the lens, we put a camera right where your eye would go when using it. Some sextants called "whole horizon" have a different mirror set up.
Hi,Chris,best regards from Bulgaria,from a future Navigator. Great movies great knowledge,everything perfect!!!
I would like to ask about the sextant you are using in those videos.What Celestaire model exactly it is?...as I am planning on buying one of these.Is it the Astra III with Trad mirror or the one with WH mirror? Love Celestial navigation. Thank you in advance ,take care. Rosen
Hi Rosen, thanks for writing. This particular sextant is the traditional split mirror. If you get a chance to use a whole horizon mirror, many people like them better. However anything will do the job. Good luck! - Chris
I do appreciate your answer, Chris.
Once I bought it,I will send a photo !......can't wait.
Thanks again for answering,and I wish 7 foot under the keel,and God Bless!
Though i wonder, you sextant isnt stable it lifted by human which is also rocking. How can you properly measure something which so much things in motion?
That is a good point Rombout, depending on the sea conditions, you sometimes need to average your height between the peaks and troughs of the waves. If you get a chance to look through one, it might clarify your point, for the most part if you assume you use a sextant to navigate on the open sea, an error of a mile or so isn't catastrophic. So a combination of knowing your height (or averaging it) and keeping yourself as steady as possible does the trick. Thanks!
Also as low as possible on the ship than, that means the least amount of motion or rocking. My father had one, but i havent touched that thing in 20 years orso.
Because the two mirrors on the sextant are consistently relative to each other without regard for the movement of the operator, it is actually much more stable than you would think. I can do deep knee bends while taking a shot and the horizon and sun do not jump around but stay right in view in a very stable manner as I screw them down to just touching.
loved it
What’s the difference between a sexton and an alidade
Hi Chris, Alidades measure horizontal angles (parallel to the sea) and the sextant can do both horiztonal (if you hold it sideways) and vertical (if you hold it normally). You would use an alidade for taking bearings from objects to plot on a chart or maybe to do some celestial nav when the object is close to the horizon. Thanks!
The you so much for the videos
Hi when bringing the sun down to the horizon with a full index mirror is it still ok to remove the object shades??
Hello Mike, So the two shades are termed horizon shades (the lower ones) and index shades (the upper ones). You should feel free to remove the horizon shades when you get close to the horizon, but the index shades should remain in place. When using a "whole horizon" sextant, you can likewise remove the horizon shades, but you should keep the index shades in place. You can experiment with the shades a bit but stay safe! Thanks!
Thanks for the info.
Hi Chris
Can you show me how to use the sextant at night?
Thank you very much
Hello Vanessa, sure thing this video should help ruclips.net/video/sa_2qF1iCqk/видео.html
Thanks!
Can we get a video of all the basic requirements for calculating long/lat w/ a sextant, watch & nautical almanac? Is a calculator, protractor, ruller... graph sheets... needed? What else?
I watched this video a few times & I don't quite understand exactly what you're doing. I'm sure it's good info, but it's just not clearly & thoroughly explained enough for me to grasp it. I saw you split the sun into 2. I think you aligned the top of the lower-sun w/ something. Heck, I really just can't tell what you did.
After watching a few more times, I see what you did. It's well explained enough. Lots covered very quickly. Another item one may need is a chart of the stars if the starcharts in the nautical almanac aren't good enough. There are brass sextants on ebay for < $20.00 I wonder if those would suffice. They're a bit small, & I'm not sure if they have lenses, but maybe one can war polarized sunglasses & use it.
ComandOr Zerxius I just looked over the $20 sextant on Ebay (BR4850B 4" Antiqued Sextant). It seems a bit small & lacks the fine-tuning device that yours had, but like you said, you don't need the seconds adjustments, so, do you think this would be adequate for measuring distance w/in 2 miles? How accurate do you suppose this might get you? 4 miles?
ComandOr Zerxius Hello, thanks for watching. I think the sextant you describe might be a little small to learn the fundamentals - I might suggest starting with a plastic Davis sextant, a used one should be fairly inexpensive. This video is part of a larger series of 11 Celestial Navigation videos which are all available on the channel. In order to present the maximum amount of information, we move very quickly, with the assumption that viewers will either pause the video or watch it a few times to accomplish the tasks. You can access all the rest of the videos on the navigation training channel (click under the video). Thanks again!
Does anyone knows where can I buy a sextant like the one in the video?
+Castiel Ryuu Hi Castiel, it is a Astra IIIB sextant - but the flame decals are custom :)
Enjoyed that
What is the name and item number of the spherical trigonometry calculator app for ipad that you refer to in your videos? Thank you. Vinceabecker
Vincent Becker Hi Vincent - there are many apps available - the one I used is called "triangle solver" but that is for plane triangles. Cruising World did an article www.cruisingworld.com/gear/theres-app about a few good boating apps, among them was EZsights for celestial navigation. I would look at a few reviews on the app stores and see what fits your needs best. Good luck!
tnx
Was pf great help..thank u😊
Thank you for existing 🎈👽🕹️🛼
Great video. Thanks for posting this. :-)
very helpful,
A good One In Plain English :)
That's so cool!
Where can I buy a GOOD sextant?
I would say the Davis plastic sextants are a decent place to start. Here is a video describing the differences: ruclips.net/video/w2xAqww_X_U/видео.html
The horizon curves and the earth spins
🤣🌏🤪🌏🤣
@@planeearther7966 m0r0n
sextant was replaced by the handheld clock hundreds of years ago, and for good reason. Any inclement weather, and you're lost
always need to correct the sextant before use! perpendicularity and side error
+edward wiseley Hello Edward, definitely. As this is an 11-part series, sextant corrections are covered in other videos. Thanks!
DOES SEXANT USE SPHERICAL TRIGONOMETRY?
+Serbian Conspiracy No, as it measures only one angle at a time : the celestial body elevation above the horizon
Celestial Navigation works because of spherical trigonometry. The angle taken from the sextant is input to a set of S.T. geometric equations that provide enough data to make your positional plot on the Chart. Some of this calculation can be seen on the videos over on my Channel
Nice explanation but anyone sees the UFO on the top right corner at min 7:04? :-)
Dude's got flames on his sextant. Freakin' LEGEND!!!!!!!!!!!!
Thanks! This is easily the clearest, best presented, and most comprehensible explanation of how to use a sextant that I've ever seen...and at a total length of 7:51, well within the attention span of at least some RUclips viewers. :-)
Wow, I always thought using a sextant would be crazy complicated... You made this piece of metal that does magic into something logical that actually makes sense.
Thank you for sharing your knowledge, very much appreciated. You are a good teacher.