Celestial Navigation Made Easy - Part 2 of 2

[@MaartenFL360]

Hi mister cpt. Nesh. I usually don't comment on the videos I see but I have been looking at these two lessons with great appreciation and I feel this really deserves a feedback. I am a commercial airline captain with a major European airline and came across many instructors during my career. I must say that your approach to teaching a complex matter is extraordinary. Well done, you are a true example of a very good instructor. The accuracy on the one hand with the tendency to look at the tables from a distance and see the meaning behind the data to understand what you are actually doing, and the keep-it-simple attitude on the other hand is a balance you totally master where many teachers will get lost. I truly thank you for sharing your experience and knowledge! Regards, Maarten Coppens.

[@MotorcycleMouse]

This is like my fifth time watching this video. I have gotten pretty good with a plastic sextant down to less than a mile sometimes but to say it takes practice is an understatement. If he draws a picture on the bored do yourself a favor and copy it down with notes on what he is saying. Once you learn to use the books it is very simple after a while. Start with the sun! Trust me then go to moon stars and planets once you are confident in how to read the tables. Remember this is a FREE video. For what you are learning others charge 100s

[@bedford61]

Sir, I have to tell you something. You are an outstanding teacher! I got myself a Davis Mark 3 Sextant, just for fun. Yesterday I did my first sightings with it and tried to find the FIX of my home, inland, through the glass of the windows and with an artificial horizon. The result completely amazed me. The latitude of my FIX is only 8.6' and the longitude only 6.2' off, compared with the GPS position. Let's see, if I can get even better with more practice... I'm really happy about this little success. The credit of my success belongs solely to you and I want everybody to know. I hope, one day you will make a video that explains to calculate a great circle, using the sight reduction tables.... It's easier to learn from your videos, than from books..... Thanks again!!

[@yachtsoho9279]

I think the key to learning something like this is actually understanding WHY you're doing what you're doing, as opposed to just plugging in numbers like a robot. I have literally just finished a 10 day commercial Celestial navigation course to complete my MCA Master of Yachts 3,000GT, and, like almost all my courses, was just taught to pass an exam. Thanks to these two videos, I now understand why I'm looking for the number, correction, position or time I'm looking for, and therefore completely understand the subject. Brilliantly explained and thank you very much for taking the time to teach this completely free of charge! Just ordered the T10 toy boat for my nephew as a token of appreciation. Should get to Teddignton, England in time for Christmas!

[@diegomartinez7420]

Here is a gentleman that knows inside out a subject, explains it with infinite patiente and wit, simplifies the complexities, makes it fun and makes you understand step by step the beauty of celestial navigation. Celestial navigation is fairly complex to understand even when it is explained to you, and I marvel at our ancestros who were able to develp this system to navigate our world. It is just pure science and a beauty. Thank you very much captain for having the privilege of your teaching.

[@philipwall2461]

I was a commercial pilot over 40 years , and I did a short course in celestrial nav about 8 years ago. Never really understood it ,but the standard of instruction was so good in the two vids. excellent .Philip wall UK.

[@vietrandy1]

Brings back fond memories of my Navy OCS Celestial Navigation class. I loved this class.

[@Gero61]

Hi Captain Nesh - I am progressing from costal-offshore to YM Ocean, having read the RYA Celistial notes, looked at a few utube's etc. I congratulate you on the best made easy, expertely explained, simplified (eg. Dec. as Longitude, GHA as 0

[@kev-the-windsurfer.]

I tried several different tutorials, but this one you have done here is by far the best. I have been thinking about learning celestial navigation for many years since I have spent most of my life on the water, but I always thought it was too hard, turns out I was wrong, I just needed the right tutor!! Part 1 and Part 2, extremely long videos but I watched them in their entirety over a few nights , I very much enjoy your approach and the way you explain things at a pace where we can digest what you're telling us rather than going too quickly. You always explained and showed differnet ways to do the same thing, you went back over things, made it all very clear....Anyway, thank you, I know its 4 years later, but I thought you might like to know people are still watching this!!

[@catalinamariei9037]

There are 6 years now, when I found them, and the only word I can say is ”BRILLIANT”! Thank you, Sir!

[@pjenkins3700]

Many thanks indeed for such patient and clear tuition. The proverbial penny has finally dropped!

[@andrewmorgan81]

As a complete stranger to celestial navigation, I found this particular set of videos, fascinating, informative and educational. Thank you for helping me overcome the mysteries by of sailing by the stars. Wonderful! Thank you Captain.

[@eliaschris2154]

Thank you very much sir. It took me a week to finish both videos, but it was worth it.

[@remomachado4488]

Hi cpt Nesh! I attended already a couple of CelNav courses, read many instructional books and was able to compute a position under the procedure and had some understanding of the process. But your way of explaining the concepts and the reasons was superb and unique. I could easily understand the whys. Thank You for your time and exceptional instructional expertise in providing us with these videos. Remo, from Brazil.

[@costakeith9048]

Excellent video, with no fancy graphics and nothing but a whiteboard you gave the best introduction to celestial navigation and the use of the tables on youtube, it finally helped me visualize what is going on. Thank you for putting this out there. It's probably asking a bit much, but I'd love to see a course in advanced celestial navigation where you go over some of the other, less commonly used, height corrections, the formulas behind the tables, and perhaps even things like lunar distances and other methods that might be classified more as emergency navigation today.

[@fqis100]

Well , thank you so much for bringing me from darkness to light in nautic celestial navigation . Much appreciated !! For quick recap start at 6:21:00

[@lvanbrus]

You are an example of excellent teaching, from,keeping it simple to some complexity each time, without losing the audience. Recap at the end. Congratulations!

[@dranandamay]

00:00:00 Introduction 00:10:00 Watch Time 00:27:00 Sextant Height 01:16:00 Dec & GHA from Nautical Almanac 03:35:00 Hc & Z from Sight Reduction Table 05:57:00 Making a Plotting Sheet 06:20:00 Practice Problems Bought the cheapest sextant from flipcart @ $12 .... will get it by next week, and then try out from my terrace 😊

[@pavaoakrap5026]

Can i ask which sextant you Got? I m curious to get one just for practice purpose at the moment and 12 bucks is good deal lol

[@shameer617]

Capt.Nesh,lot's of thanks for valuable lesson about celestial navigation

[@templetopics]

We appreciate you! Thank you for taking the time to pass the knowledge down.

[@lf6300]

Hello Captain Nesh, I am currently following my local Coast Guard celestial navigation course and your video helped me put all the pieces together. Thanks from Argentina!

[@weatonulei4081]

Great job at explaining how it all works. 4 years in a Maritime academy and no professor had ever made it so clear. Thank you so much for all your effort on producing this video, or maybe I should say this online class. Now that everything makes sense I’m definitely confident as I look forward to taking my USCG examinations for a license as 3rd mate unlimited in a couple months. Can’t thank you enough!!!

[@garyocean]

I've been ten years in commercial shipping, crossing Atlantic & Indian Oceans plus all the smaller ones between.... I did this, and do it....but didn't "Understand" . Thats because I'm British, and Capt Nesh is correct, we are taught the most complicated way possible, just to make it look difficult for us and other..... this is simply put, and so un complicated

[@yuriys3164]

Thank you for taking time to fully explain the process! Especially appreciated the time to explain the “why” as well as going through every example: sun, moon, planets and stars-and the humor mixed in all of that. Also the focus on mistakes and not editing those out. This in itself could be a college course and you’d be a phenomenal teacher. Appreciate your time and the effort to make this easy for the viewer.

[@michaellohmeyer8581]

Thank you for your response - I get it - the Hc is for the AP which if larger than the Ho means your actual position would therefore have to be further away from the GP. My sincere congratulations on simplifying what our undergraduate lecturers managed to complicate beyond belief. You have made one old sailor very happy - thank you.

[@sujittamang1802]

M a seafarer from India sir, u really helped me in my 2ndmate exams... Thank you sir, take care.

[@ccacrislan]

Absolutely brilliant, excellent instruction, thanks a lot. You are a gifted teacher….

[@sunnybangawala6042]

I really appreciate ur effort for making the cellestial navigation easy for us...both videos are really informative and kind of easy to grasp in..i am sailing as a third mate on merchant ship and ur videos are a life saver u know...cellestial navigation is a hot topic for most of the captains of merchants ships to discuss with third mate..

[@mettebahde8394]

I think you are saving me hundreds of dollars in course fees, and adequately setting me up for my first ocean training excursion next fall. Everything makes sense. Many thanks for these!

[@terencewright2223]

Excellent video. Thank you for the clear explanations for the various corrections required , and the use of the tables.

[@manuelgonzalezdiaz6702]

Great lecture. Thank you very much Sir! You teach complicated things very easy. Great teacher! (from Spain)

[@dranandamay]

I've never been to sea; will never be. Was just browsing casually and saw your Cel Nav made easy. Now Part 2. And I am already into this hobby, on land. Trying to get a sextant also. Will Lesh y're a great teacher. Wishing you Godspeed. And greetings from India 🙏

[@jockol6991]

Mr. Lesh, I just completed your course. Thanks for your clear thorough explanations. I'll go through a few practice problems and should have no difficulties at all. G. Lindquist

[@maurizioferrario1949]

Thank you so much. I have been trying to learn this art for 3 years. Now I think I finally have a clear understanding. I will need to review at least once again, but so far so good. Thank you! You are really a gifted teacher

[@federicoacker5672]

I want to really thank you for these courses (part 1 and 2), you are such a good teacher, you take the time needed, and it is obvious that you love sail and teach, both. Cheers!

[@gordonquickstad]

Thanks for the time and effort to make this teaching video. It opened up a lot of thought about our earth and it's place in the heavens.

[@rickdunn3883]

Great job. This was a great re-fresher for me. I learned Celestial Nav. at a maritime academy over 40 years ago. Practiced it at sea (on large ships) for years. We used do practice it any time not in Pilotage waters, so that our skills were up-for those few times when we really needed it. One technique for stars is to pre-calculate the stars Hs and their Azimuths, plot these on a small piece of paper, then when its "Star Time", you can actually take the stars in the east first (for evening stars) and shoot about 6 or 7 Navigation Stars within about 3 minutes. For unlimited USCG license exams - no forms are permitted, and you must use HO 229. In practice we would use HO 249 (much easier) at sea. Watch officers would keep a navigation notebook which the Captain would sometimes check your sight reduction math. We also checked the Gyro with Azimuths, amplitudes, used Lat by Polaris, and some other more advanced techniques). I never could get Moon shots to be very accurate LOPs (not sure why). We still teach this at Maritime Schools. The USNA dropped Celestial Nav training for Midshipman for a few years, and now I belie they brought it back. Great Job!

[@TippeCanoeT50]

Good note about precalculating the Hs and Azimuth of Stars so they are easier to identify and find when you are ready to take your sights. In the interest of clarity, I decided to leave out some of the finer points like this and focus on the basics of how celestial navigation works to give you a position, but I am glad you brought this point out in your useful comment! On a cruising sailboat which is often short-handed, sun sights are the most frequent type of sight since the sun is easy to find and everything on board is easier in daylight. Advancing the morning sight to the time of the afternoon sight is an easy step and although there may be some inaccuracy involved in this step, it does not usually create too large an error. However, occasionally it is nice to have multiple sights taken at close to the same time of various bodies to give multiple crossing lines of position to double check the accuracy of your work, so star and planet sights always have an important value in your celestial repertoire!

[@nicholasbeck7670]

Thanks Will. You brought it all home for me, after a 40-year hiatus. Very comprehensive and thorough. Greatly appreciate it.

[@DavidPakenham]

Thanks...never thought I would be able to grock this in just two great lessons!!! Waiting for my sextant to come in the mail then off to the ocean to calibrate/get correction numbers!! Ultimat plan is to curcumnavigate the world in a 50' junk rigged schooner im building.... Also this video is good lesson in how easy you can miss calculate...in the moon GHA calc(at 2:25:00), the hundredths position was left out and the moon got put East 100deg too short...imagine would be discarded on next calc... Thanks again for laying out so well...

[@donalroche5666]

Thank you for two excellent video tutorials. I studied celestial navigation fifteen years ago here in the UK and then forgot most of it especially anything learned by rote. These tutorial were a perfect revision tool and your method greatly helped my understanding and I hope retention.

[@kristiannielsen6804]

Do we need two star sightnings to get a position? If you easily know how far away its ground position is via the sextant, and you know in what direction you sighted the star, isn't it just to follow the line opposite of your bearing from the stars ground position X miles (your distance away from it)?

[@TippeCanoeT50]

Technically you are correct, but the problem is that the accuracy would be very low because the direction in which you shot the star is very hard to measure precisely. Even 1/2 of a degree error in the direction you shot the star when sretched out over 1000 miles or so from the ground point could cause a very large error indeed!

[@saints51]

Capt. Nesh. You give the clearest explanation for celnav I've ever seen. You really dish it up. Thanks a million, especially for the long second video.

[@kenpasseri]

Cpt Lesh, could you please do a part Three!? Going over stars and planets would be awesome. To hear your practical clear explanation would be a great service to all of us forever in your debt.

[@TippeCanoeT50]

Hi Ken, I am guessing you must have missed the section of Part 2 that covers the stars and planets. Part 2 in its entirety is 8-1/2 hours long. Let me know if you still can't find those sections of Part 2. Happy Sailing, Will

[@strannick2212]

I have always found this to be by far the best presentation of celestial navigation. He does a great job of explaining the subject, using simple language and easily understood diagrams. Not to be picky, but technically in his diagram, LHA should be 285 degrees and not 075 degrees. LHA = GHA minus longitude West. LHA = GHA plus longitude East. LHA is measured westward from observer's meridian and would be the external angle (285) of the triangle rather than the internal (075) angle. I realize that one is the reciprocal of the other, and that on entering the Sight Reduction Tables and using the 75 degree 285 degree page, one gets the same result for either value. I have never used anything other that Sight Reduction Tables in sight reduction. Would anyone know if one can use either value for the LHA when using say, a scientific calculator?

[@TippeCanoeT50]

The Sight Reduction tables give you the Z value which is the solution for the direction to the sun based on the ground point of the sun in Latitude and Longitude which you have given the tables and based on the Lat and Long of the AP. The information you are actually giving the tables, since tables work better with only 3 pieces of information to enter, are the latitude of the AP and the Latitude of the sun (Declination) and the difference in Longitude between AP and the sun's position (LHA). The question is whether you have to measure the LHA always from AP around to the West to the longitude of the sun's position. Technically you are supposed to measure LHA to the West. But sometimes it seems simpler not to do what you are supposed to do. The only part to resolve is if you were sighting to the east (morning sun sight) in which case Z = direction to sun measured from North around to East like a compass, or if Z is the mirror image of this problem as in sighting to the West in which case Z is being measured from North around to the West so the direction to the sun = 360 degrees minus Z to match our standard way of measuring compass angles from North around through East. The tables solve these two problems as though they were the same problem, which essentially they are. The mirror image of these two problems in the Southern hemisphere is solved at the same time resulting in the equations: shooting East in Southern Hemisphere, direction to sun = 180 - Z. Or shooting towards the West, Direction to the sun = 180 + Z. Z is the value taken from the Sight Reduction Tables. If the tables gave separate solutions for each of these 4 situations, it would be simpler and Z would not have to be manipulated, but the tables would be 4 times as long resulting in 4 times as many volumes of tables! If you want to use the rules given at the top and bottom of the sight reduction pages for figuring out which of these equations to apply for getting the direction to the sun from the Z value, then you must always measure the LHA to the West, and not just take the difference between the AP Longitude and the GHA (Longitudinal position of the sun). I usually know if I have taken a sun sight in the morning or afternoon (ie. shooting to the East or to the West) so I find it easier to simply take the difference in the AP longitude and the GHA position and then correct the Z value based on which of the two triangles is appropriate if I am in the Northern Hemisphere. Some people may prefer to always measure the LHA to the West in which case the formula in the tables will adjust Z correctly for the direction to the sun. In a star or planet sight where you don't always know if you shot to the East or to the West it is easy enough to compare the AP Long and the GHA of star or planet to see if the body you shot was to the East or to the West at time of taking the shot. In the Northern Hemisphere Direction to the Sun shot to the east = Z. In the Northern Hemisphere Direction to the Sun shot to the West = 360-Z. In the Southern Hemisphere Direction to the Sun shot to the east = 180 - Z. In the Southern Hemisphere Direction to the Sun shot to the West = 180 + Z. Whether you always measure LHA to the West or just take the difference between the AP Long and the Sun's longitudinal position (GHA) and call this difference the LHA, these formulas are always the same based on whether you shot to the East or to the West and depending on which hemisphere you are in and you will find yourself on the same line in the tables either way you measure the LHA.

[@strannick2212]

@@TippeCanoeT50 Thank you for the comprehensive response above.

[@joecastanza9822]

There's a VERY simple mathematical error in your Moon shot (ending near 2:37:03) which, if actually carried out to completion, puts GP MOON 10:30:43UTC at a longitude that doesn't exist. Here's how it happened: We added v=5.4' and time corr=19.8' to 194° 51.5' and arrived at 101° 76.7', which we corrected to 102° 16.7'... that should be 202° 16.7' (that's the addition error, we're off by 100) which, when we subtract 180° give's you 22° 16.7' into the Easterlies!!! Therefore... 202° 16.7' -180° --------------- -158° 16.7' ... and the negative means we're in the other hemisphere (West would have been negative, so the math is trying to say "East"). So, the solution to the GP GHA/DEC MOON 10:30:43UTC is: Dec (LAT) = S 23° 5.7' GHA(LON) = E 158° 16.7' ... which is in the Coral Sea, just East of Queensland Australia, and just west of the New Caledonia. Still, I ABSOLUTELY LOVE this course, I am enjoying it so much!!! (And I'm only 2 and a half hours into the video!!!). You're are TRULY the foregoing authority on Celestial Navigation, and you teach it MASTERFULLY. Thank you so much for doing it!!! I'm only adding this comment in case someone with less navigation experience gets confused (because I was pulling out my own hair, and I'm a retired airline pilot!!!) :P I was taught a variation on the sextant for airliner use; I've just taken up Celestial Navigation with a regular sextant. See ya on the seas!!! Dr. Joe Castanza, Chief Scientific Officer ISI-PRO at Sparta-Gateway Heliport

[@NitinKumar]

I was confused at that to simple mistake and yes I am simply loving these video no bs everything just perfect and clear to understand

[@TippeCanoeT50]

Yes, It is great that people are picking up on my slip on working out the moon shot, forgetting to bring down that one degee digit that was written in a slightly messy way out of its proper column on the white board! It definitely shows how easy it is to make simple errors if your work is not neat and tidy!

[@joecastanza9822]

@@TippeCanoeT50 STILL!!! Your course is absolutely the best, most passionately rendered video course there is. Thank you so much for providing it. I now have a Plath bubble sight for my Celestaire Astra III Pro; any time the weather's nice (even sometimes in winter, when you have to take into consideration the contraction of the metal!!!), I will go out on a nice, starry night, a red flashlight and a lit compass... It's my goal to sometime make it to places where I will have been able to use all 57 stars in the CN constellation!!! I have yet to get out onto a cruise ship to try my hand on open waters. We regularly drive up and down the East Coast from NJ to FL to visit my parents down there... we'll stop at a random spot, and I'll use my bubble sight (which, granted, makes things a lot easier than trying it on a rocking boat!!!) and I'll get my location to within about 1,200 feet every time. My record is 559 according to GPS... but, funny thing, that was due to an error!!! :P Glad you made it thru COVID; I decided I was going to learn Celestial Navigation during the lockdown. I have several sextants now. I'm a theoretical physicist by training, and you know what??? CN was something that was always scary and mysterious to me... for fear of failing miserably at it, I never tried it. When I saw your course, I was INSPIRED!!! Got myself a Davis and an artificial horizon, I was doing sun shots during the day, and you made reading the Nautical Books SO EASY for me. So, THANK YOU, Captain, for your inspiration and help!!! God bless and keep you always. May there ALWAYS be a "trinity" of stars for your to fix on. :) -Joe

[@pirateradio8336]

Wish you live long and healthy. Thankyou

[@glitchxd311]

I think you should upload more video because your video is useful I know that is 1year ago you upload this but I want you to upload more. Well done. Thank you, is a very easy listening video teacher.

[@josephlai9759]

Sir, thank you so much. Your knowledge is deep and your generosity to share it leaves us an invaluable legacy that none of us can ever thank you enough. Wishing you best of health and spirit always.

[@goaro2007]

thanks a lot, very clear masterclass. Muchas gracias !!

[@dennis6325]

I must say, both these parts are an EXCELLENT presentation. The best I have seen on KZbin. I enjoyed them very much. However, I do have a few minor critiques you may want to think about. #1: Technically, the sight reduction tables do not solve for the triangles you have drawn in this presentation. The correct spherical triangle has three vertices, one at North Pole, one at AP and one at the gp of the celestial object. #2: The sight reduction tables are NOT divided into 6 volumes because of an issue with the changing distance between lines of longitude. Hc or Z can be computed from the same equation in ALL six volumes using the same spherical law of cosines. All the sight reduction tables could be put in one giant volume or be divided up in a number of different ways. I think latitude was chosen only for convenience sake because we tend to cross oceans following lines of latitude. This allows us to use the same volume (i.e. same lighter weight book) for extended periods of time.

[@willlesh7674]

Hi Dennis, I actually think we are saying the same thing a triangle defined by the north pole and the latitude and longitude of the gp and the latitude and longitude of the ap is the same triangle as far as angles and distances as a triangle defined by the north pole, the LHA and the latitude of the gp and the latitude of the ap. There is no difference between these two triangles except that one is positioned on the globe as far as longitude and the other is not given a specific location as far as longitude. Later on in the video I refine the concept further to explain that the tables only need the ap lat, gp lat and the LHA (difference between the longitudes) to solve the problem (hence the triangle you are refering to) . Hope this is helpful.

[@dennis6325]

Agreed. Thank you for responding and thank you so very, very much for doing these videos.

[@maza2934]

Thank you captain for your video !! Greetings from Greece!!

[@filiboychenko]

Many thanks for your great work!! Very good and easy understanding explanation! Keep going and good luck!!!

[@chrisrichardson7217]

I agree with everyone else that these videos are extraordinarily well done, and the best out there, thank you so much!

[@TippeCanoeT50]

Wow, Chris, what a wonderful comment!

[@RaySmythe53]

Absolutely wonderful. Now it all makes sense!

[@TippeCanoeT50]

Watch out for the adding error in the moonshot - this is a perfect example of why it is important to write your numbers very clearly and in their proper columns. Several people have picked up on this error, but the process of the moonshot is still correct so that segment still serves its purpose adequately.

[@dranandamay]

At 06:13:00 while taking 2nd AP, you did not round off the Lat to nearest integer degree. So how will you interpolate?

[@myenglish4579]

Man! You are Awesome !!! Makes more video about Navigation, such as chart work, weather, etc

[@allendavis4545]

Thank you captainfor this excellent training.The only part that was miss out was the course line in comparisson with the line of position or the noon sight advanced to the line of position to obtain a fix. Again I want to say to you,thank you very much for all of this valuable lesson.

[@gunnarisaksson8677]

Thanks for the great tutorial.

[@arthurgarthur]

Great video. Thanks for filming, and putting it online. Now how about one on spherical trigonometry! All the best.

[@ruipaviana661]

Again, thank You from Portugal, You are realy a good instructor.

[@smrd0110]

Very nicely done. When making the altitude correction, you subtract 14.3 min. Wouldn't this give you an Ho=28 degrees, 55.2 min?

[@apovegas2403]

Thank you for taking the time and go in detail on this subject... Great job...Both, your first and the second video helped me understand these stuff. I had purchased books and watched videos before but everything seemed to be broken down in unmendable pieces. Your videos filled in a big void for us that did not go to a class for celestial navigation. Thank you again!!!

[@mrvegardeide]

Hi captain Nesh! A big and heartfelt thank you for your comprehensive teaching on this subject. In particular I am impressed how well you manage to reduce all those "ridiculous" complex explanations found in literature into clear understandable terms and techniques. You are just GREAT Will! Personally I find your videos to be the best ever on this subject on KZbin! I have however a humble request to make please. I live and sail in the eastern hemisphere and have always wanted to learn Celestial Navigation. With your help I am now almost there! But unfortunately I realise that a few terms and techniques are working slightly different in the eastern hemisphere compared to the western hemisphere. In particular I am struggling understanding how I correctly should go about to assume my position (AP longitude), and also how to correctly set up my plotting sheet for EH and Plot the LOP. What seem to confuse me is that we are going backward from 0 to -180 degrees in everything we do in my neck of the world. :-) I believe for this reason things appear slightly different and more complex to me for Eastern Hemisphere. Would you be so kind and share a few examples on how to go about for eastern hemisphere as well? All the way from taking the sight down to plotting the LOP. (I assume you must be a busy man, so regardless of this request I am anyway grateful for what you have shared already! Thanks a ton!) Thanks and regards Vegard

[@DeeJay1953]

Great course! Thank You!

[@elrohir_]

Thank you captain for the video! Very helpful!

[@troyyoung5594]

Ahoy there Cap,n Thank You for the education. After going through USN Celnav training you finally make it understandable. When you are cruising look for the S/V Bon Temps ( USA ) I invite you aboard for a visit. Capt Troy

[@dennis6325]

Instead of the CGA memory trick, you could just remember 90 minus Ho is the observed distance from the gp of the sun; and 90 minus Hc is the computed distance from the gp of the sun. Therefore, if the observed distance is greater, your actual position is further "away"?

[@TippeCanoeT50]

Right, if the observed distance is greater than the calculated distance, then you are farther from the sun than the distance from the sun of the imaginary point for which you calculated the distance.

[@harbourdogNL]

I'm doing a charting/plotting course in January and just found (and subscribed to) your channel...am looking forward to watching the videos. Thanks in advance.

[@jmlinne]

Thank you so much. I've been trying to teach myself with mixed results. I just need someone to walk me through a complete sight. There you were! Now I think I can do it. Just a little question about v - values. I'll re-watch. Hopefully headed out this August. Mexico, then Polynesia See you there

[@Herophilos1]

Congratulations on presenting comprehensive introduction to the practice of celestial navigation so clearly. I would like to add a minor point, that doesn't affect the accuracy of your instructions. Please note that the spherical triangle which Tables 229 solve isn't the one you drew on the board. Two of its vertices are, as you point out correctly, are AP (the assumed position) and GP (the geographical position of the celestial body). But the third vertex is the elevated pole (N or S pole), and not the right angle formed by the AP meridian line and the GP latitude line. You may see these triangles on page ix of the Introduction included in all volumes of the 229 tables.

[@oundhakar]

Thanks for taking the time and effort to share such an excellent course on celestial navigation. If you're in Bombay, India, do let me know, and I'll stand you a drink.

[@clausjepsen]

Finally I got it. You are a good teacher. Thanks a lot.

[@TippeCanoeT50]

Hi Claus, I am glad Part 2 worked for you. It got a bit long, but I wanted it to be clear and not leave out anything.

[@grahamdodd7331]

Great teaching of this subject

[@rogeliofinoli7759]

Excellent conceptaul explanation

[@lafpml1]

Very good explanation, very thorough

[@TippeCanoeT50]

Thank you Pierre, I appreciate the comment!

[@davecooper5951]

Great series. De-mystified so much ! Looking forward to putting it into practice when I go on board a Clipper next year. Just need to find some stars and planets in the night sky...

[@bawbawruiz4178]

i learned a lot sir thank you very much i appreciate it a lot your are very unselfish person

[@Aonghus53]

Will, thank you for your patience in preparing and presenting both Cel Nav Made Easy videos which are best I've seen on KZbin. Can anybody help me with a query re LHA which I understood should be measured westward from AP? With LL Sun sight at LT 10:20:16 on May 6th in Part 2 video LHA (measured eastward from AP) is calculated to be 18 degrees (at 6:48:00). Should this not be measured westward at 342 degrees? Or does it make a difference since sight reduction tables list same Hc, d and Z for both 18 and 342 degrees?

[@damian3885]

Thank You Cpt. Nesh!

[@MrWasim100100]

thanks nicely explained! last hour must watch! great example! i love your reviews and emphasis :) good job

[@maurizioferrario1949]

Dear Capt. Nesh, first of all as I wrote time ago, thank you so much. Thanks to your videos, which I have been viewing several times, I have learned and now I master the techniques of celestial navigation. I am now thinking of making a video tutorial in Italian on celestial navigation on my you tube sailing channel Maurizio Ferrario, and i will try to use your method. And if you give me your permission I would like to place on my video a link to yours, for everyone who can follow a presentation in English. Pls advise if I can mention you, your channel and place a link to your video in mine. Thank you very much. Maurizio

[@TippeCanoeT50]

Hi Maurizio, That will be fine to refer to my video and to provide a link between your video and my video. I am glad that you have found my video useful and informative! Best Wishes, Will

[@Zappa8891]

Thank you sir!

[@bedford61]

Hello Sir, thank you for this educational video. Even I'm able to understand and follow your explanation. I'm just learning how celestial navigation works. I have just one question, if you don't mind. In a new almanac there's an additional table for the altitude correction. It's called REFRACTION. When do I have to use this table? Do I have to use it for all altitude corrections to get the correct hight observed? I would really appreciate if you could help me out.

[@TippeCanoeT50]

Thanks for your nice comments. I think if you read the note about the refraction tables you will find that they are corrections for very low altitude sights. During the video I recommend that you not take sights under 15 degrees of elevation because the distortion from refraction of the light coming through the atmosphere at such low angles is hard to predict and causes so wide a potential for errors. If the sun only becomes visible just before it gets to the horizon, then you can use the refraction tables to make additional corrections, but don't rely on the results being nearly as accurate as higher sites would be. I am glad that you brought this point up since I did not get to mentioning the refraction tables during the video presentation!

[@adamscott7625]

Do the corrections tables change by year?

[@davesanders5403]

Thank you so much. The mystery has gone and the fog lifted. See you in Auckland 2021 in your new boat??

[@maikin15]

Thank you, thank you, thank you!!! Finally it's getting clear to me. Just need to practice now

[@rumenchoooo]

Thank you!

[@sanchopabsta]

This is a very good course. There is one thing I do not understand. Why is it that on top of Ho, we de not measure the angle (magnetic) of the celestial body we're shooting. Would that not give us a fix along the circle defined by the radius 90-Ho?

[@sanchopabsta]

Just realized that the answer is at 3:41!

[@TippeCanoeT50]

Yes, in theory that would work, but in reality a compass angle stretched out over thousands of miles might give you as little as 60 miles accuracy for your fix depending on the accuracy of your compass and your ability to get a compass angle towards something high up in the sky. Taking a second sight to give two lines of position that cross and give you your position is easy and accurate.

[@arvilmogensen1945]

I am learning this subject using your videos for which I an appreciative that you took your time to prepare. My reason for wishing to learn is connected to my fascination with explores of North America. Not as far back as Francis Drake, but to Captain Cook and land explorers like David Thompson. Padding upstream and walking over land, would see rather modest distances traversed. So my curious question is ..... if on land, if you took a couple of Sun shots every day, you could nail down your azimuth and the successive LHA circles would easily overlap as traverse distances are likely 20-25 miles a day. I not saying it was easy, but overlapping circles provides a succession of circles and Lat ad Long that are validated each day. Is this consistent with your thinking? On the other hand it must have been brutal doing all the Spherical Trigonometry. For Francis Drake who navigated without a modern Sextant who must have used an Astrolabe and Dead Reckoning, I think the man must have been the best navigator ever, perhaps even better than Magellan.

[@petewalker6464]

Great videos! Thanks! It all makes perfect sense now. Just a quick question, when you’ve explained SHA, you realised straight away that you’re not gonna see Venus at your longitude in this example. (129 deg & GHA Venus 240 deg). How did you know so quickly? It’s 111 deg (6660 NM) away, so below the horizon but where, roughly, would you you be able to see until? Thanks again. Pete walker

[@TippeCanoeT50]

A simple answer would be 90 degrees, but that would only be true for when you and the celestial body are both on the equator. The real answer depends on your latitude, because as your latitude gets higher and higher you can see many things with an LHA that is significantly higher than 90 degrees until up near the pole (North or South) you can see bodies with any GHA. The pages of the sight reduction tables don't compute answers for LHA values and Latitude values that would make a body invisible because the body would be below the horizon. Where the table stops on each page is where something becomes invisible.

[@petewalker6464]

@@TippeCanoeT50 thanks! That makes perfect sense.

[@jdengelb]

Really informative and well done

[@magg.consultingmagg.consul6580]

i suppose there is a error in the calculation of the correction of the GHA of the Moon 102°16.8' instead of 202°16.8' Please give me an answer. You are really a good professor!!!!

[@TippeCanoeT50]

I think this was a good example of why it is so important to keep your number columns lined up and to write neatly - somewhere I dropped a 1 because it was too far over to the side and not lined up. Working on a white board is a little harder than using a piece of paper.

[@nickkouf7436]

Great teacher!

[@Pacific.Marine.Captain]

how about a electronic voice recorder, start it at a "certain" time, and then when sighting say mark, then can go back through the audio and get time difference from when it started to when one "says mark" ...... just an idea :)

[@StanpapiTV]

Thank you so much Will!

[@TippeCanoeT50]

It was fun to do! Glad you enjoyed it.

[@BenAmoz]

This may sound crazy... at 2:27:50 is the GHA with hour And V correction not 202 deg 16.7 mins?

[@garyocean]

Thats what I saw..... just shows who's awake watching this. which is brilliant by the way

[@rupertdunn5578]

Not the first time it’s been mentioned but I chuckle every time I open this. Navigation made easy in a 7 and a half hour video…😂😂

[@davidbell3815]

Capt. Nesh. The section on the Moon from about 2.25.00 is (IMHO) a bit error strewn. As has already been pointed out elsewhere, your GHA is out by 100° because you missed the '1' (hundred) figure in your adding up. Also, it looks like you forgot to factor in the minutes and seconds correction for the DEC which should add a further 7°19.8' to 23°5.7'. This gives a DEC of 30°25.5' ............or am I missing something too?? Thanks though for taking the time to produce the video. I wanted to re-visit astro navigation having not used it anger for a few years. Your explanation is easy on the eye and the ear. Add to that the fact that (I think) I've been able to find a problem such as this, shows that I'm getting a grip on the subject matter.

[@TippeCanoeT50]

You are entirely correct about those errors. I wish I could say that they were entirely intentional to demonstrate how easy it is to make simple errors, but I fear that was not actually the case! Good job seeing where the mistakes lay!

[@sbsbsbsbsbsbsbsnsn9008]

Sir, i wonder how to calculate how long time will stars be visible on my location and which stars ? For example my latitude 30 degress north and can i see at the sky the stars which's declination 20 south

[@loskrochn7338]

Thanks i think i will get the idea. One question. The altitude corretion.. it says minus but the calculation was plus... did i miss a point?

[@goaro2007]

4:16:37. LHA because west should be 285 º. Because is W its correct or not ?

[@metincakmakc1775]

I had founded 285 ° too..

[@TippeCanoeT50]

You will find that if you enter the sight reduction tables with LHA of 285 degrees you are on the same line as if you enter the table with LHA of 75 degrees, either way you get the same H computed. The only difference is that you have to correctly figure out the Z to Z n based on which triangle you are in since the tables solve the four similar triangles as though they are the same problem. If you are in the Northern Hemisphere and you took your sighting to the East then Zn = Z. If your are in the N hemisphere and you shot to the West, then Zn = 360-Z. If you are in the Southern Hemisphere and you shot to the East, then Zn = 180 - Z. If you are in the Southern Hemisphere and you shot to the West then Zn = 180 + Z. All four problems are the same problem and give the same Hc. It is just because we like to measure direction from North around clockwise. In the case where you are in the Northern Hemsiphere and shot to the East, the table Z is measuring correctly from North around clockwise to the East. In the case where you are in the Northern Hemsiphere and shot to the West, the table Z is measuring from North around counterclockwise to the West. If you are in the Southern Hemisphere and shot to the East, then the Z value is measuring from South around counterclockwise. If you are in the Southern Hemisphere and shot to the West then the Z is measuring from South around in the clockwise direction. If you know which of these four triangles you are in you can just take the absolute difference for LHA and easily compute your Zn. If you want to use the rules at the top of the page in the Sight Reduction Tables, yes, then you must always measure LHA around to the West. You will find either system gives the same results, so just choose what is the easiest way for yourself. The absolute difference usually involves simpler math in getting an LHA but you must then think a little more about the relationship between Z and Zn. I usually know whether I shot to the East or to the West, so I have no trouble knowing if Zn = Z (to the East) or if Zn = 360 - Z (to the West) when I am in the Northern Hemisphere. When you first cross into the Southern Hemisphere you need to rethink the equation for getting Zn from Z, but as long as you stay in the Southern Hamisphere there are only the two possibilities of Zn = 180 -Z or Zn = 180 + Z. You can always chec whether you shot to the East or to the West by comparing your AP Longitude with the GHA of the celestial body. Basic rule if you are located in the Northern Hemisphere either Zn = Z or Zn = 360 - Z. When you are located in the Southern Hemisphere, Zn = 180 - Z or Zn = 180 + Z. Not too hard to figure out which should be correct - at least you always have a 50% chance of being correct if you know which hemisphere you are in since there are only two options for each hemisphere!

[@PilotBrazil1976]

At 06:48:42 the LHA shouldn't be 342° instead of 018°?