The basics of the sextant explained by Tom Cunliffe. ©Tom Cunliffe

A quick look at the basics of Tom Cunliffe's sextant from his boat on the Beaulieu River.

Пікірлер: 81

  • @theartfulbodger
    @theartfulbodger3 ай бұрын

    Nearly 40 years ago I met Tom when I tied up on a visit to the Beaulieu river. After years of reading his articles in the mags. I was pleased to have a chat with him and found him a very friendly fella! When I saw his book on astro in a bookshop I bought it because I liked him, and I was struggling with Mary Blewitt's very good book on the subject. Tom's book should be called "Astro for dummies" because it taught this dummy well enough to cross the Atlantic and the Pacific purely with a sextant and tables and compass. Once I was "hands on" with using my sextant and finding a position, Mary Blewitt's book made more sense to me and filled in more detail. Very pleased that a chance meeting with a very nice guy led to solving my navigational learning issues. Thanks Tom

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 ай бұрын

    Hi Colin. Good to hear from you after all these years. Thanks for your kind remarks. I'd like to put your words up on my website in the book section. OK with you? All the best Tom

  • @theartfulbodger

    @theartfulbodger

    3 ай бұрын

    @@TomCunliffeYachtsandYarns By all means Tom, I hope it brings in a few more sales. Your book was a game changer for me with astro, many thanks for writing it. All the best Colin

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 ай бұрын

    Many thanks! It's up on my site now. Tom

  • @aljotock
    @aljotock5 жыл бұрын

    I could listen to you for hours! So relaxed because you’re so knowledgeable!

  • @oldsailor5711
    @oldsailor57115 жыл бұрын

    Everybody in the Netherlands declared I was nuts with my walker and sextant and up to date navigation tables, they say that it's useless nowadays, it maybe is until the battery quits in the middle off an ocean. I still use it regularly just for fun and it keep u up to date with it

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    5 жыл бұрын

    So do I, Old Sailor. It's fun too and it's good to see a growing number of young sailors taking an interest - at least in the English-speaking world

  • @grafitember

    @grafitember

    3 жыл бұрын

    @@TomCunliffeYachtsandYarns Not only in the English-speaking world! We don't have seas and coasts, but curiosity here, in Hungary. Cheers from here! I love your work.

  • @AfricanFlightStar
    @AfricanFlightStar3 жыл бұрын

    Always wanted to learn how to use a sextant, now you've convinced me to do it! Was going to make one using my 3D printer (many plans avail online) but I also love a tool with history attached to it, so will see if I can find a genuine WWII era sextant out there. Thanks for sharing that 👍🏼☺️

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 жыл бұрын

    Hoping to make a series of videos about sextant use in the next year which will be up on my website. Those old sextants are lovely, but beware - some of them have been too highly polished and you can't read the figures. Tom

  • @suzyqplacet
    @suzyqplacet8 жыл бұрын

    In a perfect nutshell! This subject always makes me chuckle. In our travels we have come across private gin-palaces and other such floating temples to technology, absolutely laden down with more electronic equipment than they can use or need and yet, these monsters have been stuck in port because they have some sort of ill-function! In our old 1912 floating home we had what I feel was the basics: a sextant, a Walker's Log, a lead-line with chewing gum on the bottom, a WW2 Spitfire compass and a 1946 Dorman diesel engine , a large whale-gusher hand pump, some sturdy sails and ... that was IT! No radio, no depth-sounder, no GPS, just good charts, plenty of time , common sense, a hammer and screwdriver and we NEVER ONCE got stuck in port by anything other than a howling gale. I'm really happy that someone has seen sense - not having the basic "old-fashioned" material could cost lives. Well done U.S. Navy!

  • @750count

    @750count

    3 жыл бұрын

    I absolutely applaud your style

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 ай бұрын

    Suzy. You've said it all, really. So many people fall into the trap you mention. I've got one foot in it myself these days and I often remember with deep happiness the days when we sailed the seas exactly as you have described. Thanks for taking the trouble to remind us all of what matters. All the best Tom

  • @suzysaudiostorycorner1366

    @suzysaudiostorycorner1366

    3 ай бұрын

    @@TomCunliffeYachtsandYarns Hi there, Tom! How lovely to hear from you. Yes, as time goes on we seem to be more and more dependent on electronics and the cyber life - quite frightening! But, comforting to know that in the maritime domaine one can chuck it all overboard where it belongs and still be safely independent. I hope you and your wife are in fine form and that you are still happily sailing the seven seas. All the best, as ever, Suzy

  • @Blastfence1
    @Blastfence12 жыл бұрын

    Tom’s book 📖 on celestial navigation 🧭 arrived today just got it out of the mailbox 📬 looks wonderful can’t wait to dig in! The entire book 📕 is full of wonderful color illustrations. I highly recommend buying Tom’s book 📖!

  • @Ploddingalong67
    @Ploddingalong674 жыл бұрын

    Shakespeare and sextant, a cultural hit rare and exciting. Great to have a basic explanation of this art. Yet to be learned by yours truly but looking forward to doing so. Thanks for the post.

  • @robinj.9329
    @robinj.9329 Жыл бұрын

    The "Marine Sexant" is both simple and wonderful. Using only some basic principles of optics, physics and mechanics, we have an instrument that has been used by Mariners, merchants and Explorese to navigate the world since the 1700's. From Captains Cook and Blye. To my Grandfather in the 1960's and 70's. And is still used today by "Real" sailors and Mariners. If you don't fully trust GPS, you need to understand Celestial Navigation.

  • @reloadncharge9907
    @reloadncharge99075 жыл бұрын

    Good one.....my old Heath sits proudly in its box onboard my cat...ready for the day, charts and almanacs at hand! Thanks, Andrew

  • @alwynjones7218
    @alwynjones72184 жыл бұрын

    As always Tom, a very interesting and Informative post, time I added it to my skills.

  • @maxflight777
    @maxflight7773 жыл бұрын

    Clearly, before inertial navigation was adopted, this was the only method of navigation for aircraft out of range of ground nav aids. For example, when crossing oceans. If you look at the flight deck on an any 747, a sextant could be installed into a hole in the ceiling, just aft of where the flight engineer used to be seated. An adjacent lever is pulled to open the outside end of the hole. The snug fitting sextant was then pushed a few inches further into the port so as to protrude outside the cockpit roof.

  • @tincoffin
    @tincoffin4 жыл бұрын

    I remember my dad learning how to use one . He was sitting on the shore at Lymington not far from where Tom is now and found himself in the middle of Worcestershire . It takes practice.

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    4 жыл бұрын

    I often take my students down to Barton on Sea as you get a good southern horizon from there. In fact, I have a pupil coming tomorrow, so let's hope the fog doesn't roll in. Tom

  • @tincoffin

    @tincoffin

    4 жыл бұрын

    @@TomCunliffeYachtsandYarns Many thanks for your reply. Just to warn you - they now charge for the car parks which used to be free from October to March . There is usually a space on the sea front at Barton .

  • @karlsmith5935
    @karlsmith59358 жыл бұрын

    another fine little video tom keep up the good work kind regards Karl

  • @garygerard4290
    @garygerard42903 жыл бұрын

    best 5 minutes on U Tube, thank you

  • @PrinceKlutz
    @PrinceKlutz7 жыл бұрын

    As always another fine vid, Tom!

  • @TermiteUSA
    @TermiteUSA4 жыл бұрын

    On the Chesapeake as a kid I watched my pops practice for his USPS Navigation class. The sky now has about 30% of the stars visible with night city lights over the horizon from the WNW thru the NNW. Still love it when anchored up though.

  • @AndyUK-Corrival
    @AndyUK-Corrival6 жыл бұрын

    I bought a Heath Sextant a couple of years back but it needs calibrating so need to get it to Mr Robinson in Hamble to look at. Mirrors are a bit crusty too but should be ok. Then I need to get to work as I have not had a good crack at mastering the Sextant but it is something I want to do. Thanks for this as it has prompted me to get on to it. Andy UK

  • @williewonka6694
    @williewonka66944 жыл бұрын

    Excellent lesson in a nut shell from a man of greT experience, Thanks Tom

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    4 жыл бұрын

    So pleased you enjoyed it John.

  • @sailingcorribeemwera
    @sailingcorribeemwera3 жыл бұрын

    Great little vid, thanks, think if I went across the oceans I'd get into this

  • @abidelao9221
    @abidelao9221 Жыл бұрын

    This video is great!!

  • @blik2108
    @blik21088 жыл бұрын

    Excellent. I hadn't thought about plotting 2 latitude lines a few hours apart. Much easier than timing the highest point and then working out longitude I guess. realistically how accurate have you found it over the years

  • @VGrillone
    @VGrillone3 жыл бұрын

    Wonderful Tom!

  • @captainheather
    @captainheather4 жыл бұрын

    Oh how I’d love to see you do a whole class on Astro navigation online!

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    4 жыл бұрын

    Well, I have plans to do some Masterclasses on my website www.tomcunliffe.com. At present, I'm expanding it, but watch this space. Tom

  • @MrFergus53
    @MrFergus535 жыл бұрын

    Tom I maybe late with this comment but in a nut shell thanks for the quick understanding of why the sextant is used, Having spent my youth in the Navy until I finished up I was in the Nave Dept. as a Radar Plotter and even though I saw it being used a lot by the young snottys learning their seamanship I didn't know how too use one even though I could have to round out my education in navigation at sea. now mostly I watch you tube channels of other SVs only one of them I have seen (though they have all the Nav aids) they still use the sextant (a Canadian Cpl)so not all is lost as most channels that I watch all use the nav aid they have and astonishing enough they don't possess a sextant....

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    5 жыл бұрын

    Hi Mr F. I believe that the US Navy have brought celestial navigation back into their syllabus. Certainly over here in UK a rudimentary knowledge is required for the RYA Ocean Yachtmaster.

  • @iainlyall6475

    @iainlyall6475

    3 жыл бұрын

    @@TomCunliffeYachtsandYarns ryan on sailing kittiwake is practicing with a sextant for navigation. nobody else that i'm aware off.

  • @mikedale6783
    @mikedale67833 жыл бұрын

    Great lessons ! Thanks ! What size boats do you use to cross the Atlantic ? Keel stepped mast ? Also, what type keel, if you would ,please ! Thanks.

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 жыл бұрын

    Hi Mike. Pleased you are enjoying the vids. There's no straight answer to your question, but for me it's a keel-stepped mast and a full keel. You can read more about hull forms etc in my book, 'The Complete Ocean Skipper'. It's available from my website www.tomcunliffe.com. I'll even sign it for you! Tom

  • @sailingluckybear1045
    @sailingluckybear10455 жыл бұрын

    This is a Skill I do need to learn, Thank you for this video, I cant wait to get a Sextant and start practicing :)

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    5 жыл бұрын

    You won't be sorry. Buy the book 'Celestial Navigation' from my website and I'll sign it for you.

  • @sailingluckybear1045

    @sailingluckybear1045

    5 жыл бұрын

    that would be great, thank you! I need a month or so (been unemployed for 3 months) need to stabalise alittle then I will grab it for sure.

  • @c5back9

    @c5back9

    3 жыл бұрын

    Well, I hope things have improved for you since last year, but given all this COVID, I wouldn’t be surprised to hear that times are still tough. How about an update though? Have you been able to get Tom’s Celestial Navigation book?

  • @sailingluckybear1045

    @sailingluckybear1045

    3 жыл бұрын

    @@c5back9 Hi there, Things have been not great the year started good with more work then the last 3 years.... but March all my contracts and jobs got cancelled and back to no work since the lockdown.... I am living at the house where will build the boat, and have cleared the land and did everything can do that does not include a big expense.... just need some work again and moving forward.... hope by November something may come up..... 8 months with no work as an expat is very hard.... no work means 0 money.... if was in Canada at least have unemployment insurance and welfare, here I have what is in the bank..... and thankful a low cost of living (about $300 a month all in)... wow long reply :)

  • @jimkobe64
    @jimkobe644 жыл бұрын

    Fascinating!!

  • @Inkling777
    @Inkling7774 жыл бұрын

    In Sailing Alone Around the World Joshua Slocum mentions navigating with an old alarm clock that had only a minute hand. I've heard that can be done using sightings of the moon. If you get a chance, you might explain how that is done. I assume that's the same two-sighting trick with the minute hand telling the time between.

  • @TermiteUSA

    @TermiteUSA

    4 жыл бұрын

    Joshua was amazing. Maybe he was really Spock in the holodeck.

  • @jonelliott9157
    @jonelliott91573 жыл бұрын

    You’ve just inspired me to get a sextant, learn it and put it to work. Thank you, Sir!

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 жыл бұрын

    That's great news Jon. Do buy my book 'Celestial Navigation' which will help you get to grips with it. It doesn't cost much and it's available on my website www.tomcunliffe.com I'll even sign it for you! Tom

  • @jonelliott9157

    @jonelliott9157

    3 жыл бұрын

    I’m on it! Thank you, Sir!

  • @Dj1deck
    @Dj1deck2 ай бұрын

    Hi Tom, if we’re using the horizon to establish horizontal on the surface of earth in order to obtain an elevation angle, then the sea in this case must be horizontal and not curved, would you agree ?

  • @robertlafleur5179

    @robertlafleur5179

    29 күн бұрын

    Would Tom agree? Short answer: No. Long answer: NO. Celestial Navigation is done with Spherical Trigonometry, that's SPHERICAL as in SPHERE. Spherical trig does NOT work on flat surfaces hence Earth is a sphere. Could you solve this Celestial Navigation problem using ''flat earth science'' only since you seem to think that seas are flat and not curved? Here are 3 star sextant's sights: The date is July 6, 1993. Time UTC Star Sextant height 14:38:33 Fomalhaut Hs = 20°52.0' 14:41:37 Capella Hs = 26°01.0' 14:43:05 Vega Hs = 38°47.7' Height of eye = 9 feet. Sextant index error = 1.5' on the arc. Where was the observer? Remember, you can only use ''flat earth science''. Show all your ''flat earth science'' calculations, you can't cheat by using globe science. No flat earther has ever demonstrated flat earth Celestial Navigation. Good luck!

  • @Dj1deck

    @Dj1deck

    28 күн бұрын

    @@robertlafleur5179 Tom would be incorrect then

  • @robertlafleur5179

    @robertlafleur5179

    28 күн бұрын

    @@Dj1deck Why would Tom be incorrect? Oceans do curve.

  • @Dj1deck

    @Dj1deck

    27 күн бұрын

    @@robertlafleur5179 incorrect sea level is a mean sea level

  • @robertlafleur5179

    @robertlafleur5179

    27 күн бұрын

    @@Dj1deckMean sea level is the average height of the sea between high tide and low tide. It does not mean that oceans are not curved.

  • @seanmulligan1339
    @seanmulligan13395 жыл бұрын

    Well their warships keep colliding with folk🐳there is also the equation of time that should be mentioned perhaps we should have sundials aboard🐳🐳🐳

  • @LeonardSkinnerOfficial
    @LeonardSkinnerOfficial8 жыл бұрын

    Only Tom Cunliffe could sum it up so perfectly :-) Now, if only the boat would let me afford a sextant, it's one or the other, I can't have both!

  • @ximono
    @ximono24 күн бұрын

    0:33 "But anyone with any brains at all takes one with him, and he knows how to use it." A brain, you mean?

  • @williamturner1517
    @williamturner15173 жыл бұрын

    March, 1986, I was super cargo on a freighter from Germany to Texas. Mid way across the Atlantic, I ask the 2nd mate, Do you have a sextant ? "I'm sure we do, somewhere."

  • @pdczrwnskz
    @pdczrwnskz2 жыл бұрын

    Neat.

  • @nickwebb9290
    @nickwebb92903 жыл бұрын

    Having a sextant and being able to use it makes serious sense, who wouldn’t not have one or the lanyard to go with it

  • @redjacc7581
    @redjacc75813 жыл бұрын

    always learn the fundamentals, you just never know when tech will fail.

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 жыл бұрын

    Well said. Tom

  • @guillermogouldburn763
    @guillermogouldburn7632 жыл бұрын

    I'm bald at 30 and look at you.

  • @gurglejug627
    @gurglejug6273 жыл бұрын

    Astro Nav is back on the curriculum not least because the Russians can jam GPS signals

  • @DaveWatts_ejectamenta

    @DaveWatts_ejectamenta

    2 жыл бұрын

    Jamming the entire ocean would be quite difficult I think, a bigger problem is if they decide to turn GPS off altogether for non-military people.

  • @karhukivi

    @karhukivi

    2 жыл бұрын

    @@DaveWatts_ejectamenta They don't need to jam the entire ocean, have a listen to what this navigation officer says: kzread.info/dash/bejne/a319r9SkYLTYebw.html

  • @jonnypatwilkinson173
    @jonnypatwilkinson1732 жыл бұрын

    Works on a plane note a globe though, right.

  • @iveneverseensuchbehaviorin5367

    @iveneverseensuchbehaviorin5367

    Жыл бұрын

    doesn't work on a flat earth. go find a flat earther that can explain how celestial navigation works. you cant because there are zero flerfa who know how celestial navigation works.

  • @entangledmindcells9359

    @entangledmindcells9359

    Жыл бұрын

    Nice try Jonny, So tell us how this is possible. Its all based on Celestial Navigation. Two people on opposite sides of the flat earth with their backs to each other look south and see the same stars. They head further South meaning they are heading away from each other. The same stars they see, get higher in the Sky meaning they are getting closer to the GP. So how can two people heading away from each other can at the same time be getting closer to each other.. I can explain it on a Globe. Can you explain it on your Flat earth?

  • @rocketspushoffair
    @rocketspushoffair3 жыл бұрын

    It's not 93 million miles away. A sextant is "an instrument used to measure the altitude of any object above the surface of the earth" and that includes the sun. Great video by the way. But you and I both know, you are not using 93 million miles away in any calculation, let's be honest here. :)

  • @TomCunliffeYachtsandYarns

    @TomCunliffeYachtsandYarns

    3 жыл бұрын

    Thanks for this. You're right of course, but the scale of the Universe serves to explain the sheer wonder of all this to people unused to thinking in these terms. Astro navigation relies, of course, on angular distance not linear., but if one says, do you know that the sun's declination varies though 46 degrees from summer to winter, they'd probably blank you. Mention the in-line distance and we all sit up.