Yachtmaster Ocean

[capnsensible]

Navathome is totally brilliant with superb support and classy instructors.

But I would say that, my wife is one of them!

All three ladies are experienced ocean sailors and the help site is open from 0900 to 1900 every day.

By Co incidence I'm teaching it in the classroom this week in Puerto Banus......that's just added for pose value.

But if anyone wants to pm me with questions, please do so. Horses mouth and all that.

 

[capnsensible]

I’m wondering why you’re using Aries in your example? I imagine that >95% of all sights taken by recreational sailors will be of the sun. The passage of the sun is a fairly simple concept to grasp. Aries plus Sidereal Hour Angle of a selected star is a more difficult concept and quite a long way into the learning syllabus.

It’s always fun and enjoyable to discuss celestial navigation.

Don't need sha when you got vol 1 selected stars. Unless you are so bored on a moony night you want to reduce a star that you actually recognise.

Cue some old master mariner telling us how they did it with a bit of papyrus and two sharpened match sticks.

 

[MINESAPINT2]

I’m wondering why you’re using Aries in your example? I imagine that >95% of all sights taken by recreational sailors will be of the sun. The passage of the sun is a fairly simple concept to grasp. Aries plus Sidereal Hour Angle of a selected star is a more difficult concept and quite a long way into the learning syllabus.

It’s always fun and enjoyable to discuss celestial navigation.

When I studied Celestial Navigation for my own amusement I broke it down into bite sized pieces and determining GHA Aries was one of the bites. It is remarkably straightforward, gets a person used to using the tables and no declination to consider.
In the 2 books I have on the subject there is no need to consider Sidereal Hour Angle. In Cunliffe page 53 there are tables which are entered with Latitude and Local Hour Angle where the Hc and Zn are given for the 7 best stars. I am aware there have been and probably still are many methods of Celestial Navigation and as I have not done the RYA course I am unaware which method they use.

Obviously I realise this is pointless if no one has Cunliffe book or if no one is interested but here is another question...............

Determine the global position of The Sun, Greenwich Hour Angle and Declination May 1st 17h 14m 02s Time Zone +8 Watch Error 23 seconds SLOW.

Mike

 

[[3889]]

Having had the dubious pleasure of doing both, I thoroughly recommend Skippers Online (formerly known as Kipper Sailing) over Navathome.

Clearly both are qualified instructors, but Navathome comes across like a retired computer programmer decided to create a website, but he doesn't have any experience of user interface design and everything is a bit cludgy and clumsy. You can't navigate through the answer fields using your tab key, and they took exception when I complained about it. When I did it a couple of years ago they were still using flash animations, and the site had to be whitelisted in Safari.

I did YMO theory with Navathome and I have to say the experience wasn't great. Best way I could describe it is learning by rote to get the certificate (which I did). Interface was very poor compared to studying online with the OU and on the one occasion I sought additional tutor support it was just a reiteration of the text in the RYA documentation. I followed the instructions and completed the exercises but had very little understanding of astronav at the end. After the course I spent a day at sea with a friend who is an astronav nerd and my comprehension expanded exponentially.
Navtathome was half the price of a 1 to 1 course I was offered and without the hassle of of travelling but despite that I wish I'd done the training face to face.

 

[Skylark]

When I studied Celestial Navigation for my own amusement I broke it down into bite sized pieces and determining GHA Aries was one of the bites. It is remarkably straightforward, gets a person used to using the tables and no declination to consider.
In the 2 books I have on the subject there is no need to consider Sidereal Hour Angle. In Cunliffe page 53 there are tables which are entered with Latitude and Local Hour Angle where the Hc and Zn are given for the 7 best stars. I am aware there have been and probably still are many methods of Celestial Navigation and as I have not done the RYA course I am unaware which method they use.

Obviously I realise this is pointless if no one has Cunliffe book or if no one is interested but here is another question...............

Determine the global position of The Sun, Greenwich Hour Angle and Declination May 1st 17h 14m 02s Time Zone +8 Watch Error 23 seconds SLOW.

Mike

Breaking it down into bite size pieces is very commendable but I’m not sure of the point of looking-up Aries for the sake of it ?. Use it to add Sidereal Hour Angle (also Dec) from the Almanc Stars. But, unless you are Patrick Moore, I know of no sailor who can identify a star (now there’s a challenge ?).

AP3270, Vol 3, is the Table for selected navigational stars, the one you’re quoting from Sir Tom’s text book. No need to know their name, just set sextant altitude, turn to azimuth during the twighlight observation period and, as if by magic, the little bugger should appear in the telescope (providing it has decent optics) ?

No criticism implied, Mike. I’m a bit of an anorak so always happy to discuss Celestial, especially if it leads to my learning something new or, even better, getting others to take a look ?

 

[MINESAPINT2]

Breaking it down into bite size pieces is very commendable but I’m not sure of the point of looking-up Aries for the sake of it ?. Use it to add Sidereal Hour Angle (also Dec) from the Almanc Stars. But, unless you are Patrick Moore, I know of no sailor who can identify a star (now there’s a challenge ?).

AP3270, Vol 3, is the Table for selected navigational stars, the one you’re quoting from Sir Tom’s text book. No need to know their name, just set sextant altitude, turn to azimuth during the twighlight observation period and, as if by magic, the little bugger should appear in the telescope (providing it has decent optics) ?

No criticism implied, Mike. I’m a bit of an anorak so always happy to discuss Celestial, especially if it leads to my learning something new or, even better, getting others to take a look ?

Hi Skylark,

Just checked in Mary Blewitts book.

AP3270 Vol 1 Selected stars
AP3270 Vol 2 Lat 0 - 39 Dec 0 - 29
AP3270 Vol 3 Lat 40 - 89 Dec 0 - 29

Appears capnsensible (post 22) also of this opinion.

I do not understand what the issue is regarding looking up GHA Aries, it is just practice using the tables. Once you have looked up 50 or 100 GHA's and Declinations, Aries, Sun, Venus, Mars, Jupiter, Saturn and Moon it gradually starts to become less onerous.

Mike

 

[Skylark]

Hi Skylark,

AP3270 Vol 1 Selected stars

Thanks for the correction, time for an appointment at Specsavers ?

I do not understand what the issue is regarding looking up GHA Aries, it is just practice using the tables. Once you have looked up 50 or 100 GHA's and Declinations, Aries, Sun, Venus, Mars, Jupiter, Saturn and Moon it gradually starts to become less onerous.

Mike

No issue at all, if that’s what you want to do and it makes you happy. Practice is good.

 

[laika]

I imagine that >95% of all sights taken by recreational sailors will be of the sun.

unless you are Patrick Moore, I know of no sailor who can identify a star (now there’s a challenge ?).
[…]
No need to know their name, just set sextant altitude, turn to azimuth during the twighlight observation period and, as if by magic, the little bugger should appear in the telescope (providing it has decent optics) ?

Based on people I've spoken to I suspect you're in the main correct but I find it a little surprising that these days when there's no actual *need* to learn astro people who do bother then do the bare minimum. 30+ years ago when it was a necessity for most small boat ocean sailors yes I see the motivation for only doing the bare minimum but now surely it's an "enthusiast" thing so why would one want to just get by with sun sights?

On the star-spotting front, on an ocean passage it doesn't take long to learn what your first rising stars are and where they'll appear. A few days in everything becomes much easier as a consequence. There's not really that much else to do on night watch on an ocean passage other than stare at the sky: I take my little colins gem book of the night sky with me. While my ability to name the constellations and brighter stars varies, after 3 weeks at sea it's usually pretty good.

 

[RobF]

I've got many of the books.

• Mary Blewitt is good but brief.
• I found Langley Price and Ouvry to be unpenetrable*
• Cunliffee is good and clear
• Gerry Smith was probably the best of the lot.

I do agree that it's hard to study out of a book. When I made a mistake with my calcs (which was almost inevitable when I was learning), I found it very hard to find the root cause. Usually, it was a basic error in one of the sums or one of the lookups.

First Class sailing do a Zoom style YM Ocean course. Their instructor (Nigel Rennie) is excellent.

It's worth noting that any exams you do via Distance Learning do not exempt you from the written exam in the learning. You only get exemption if they are undertaken in exam conditions under the supervision of an RYA instructor. The bottom of this page provides further details: Yachtmaster Ocean Theory Course | First Class Sailing

* Excerpt of text from Langley Price and Ouvry. This is on Page 8 - so it's part of their introduction to celestial navigation.
"The angle subtended at P (the elevated pole) between PZ (the observer's meridian) and PX (the star's meridian) is the local hour angle (LHA of the star. "

 

[down...2 greens]

I did the Navathome course and had the written exam invigilated by an RYA YM Ocean instructor (to benefit from the exemption later). It served its purpose for this but I was not a fan of the course overall. The interface was old-fashioned, the content had quite a few errors and inconsistencies and if you were relying on this as your only learning source I think you might struggle to achieve any real understanding (although you should be able to mechanically follow the rote proforma steps adequately).

One positive was that feedback from the instructor team was very quick, with responses to questions sometimes coming within half an hour or less. I did rather feel that speed of response was prioritised over content though - in the end I pretty much gave up asking questions because the replies often didn’t actually address the queries raised.

Overall an in-person course is probably hard to beat. As a substitute I’d recommend a good video introduction to grasp the concept (try searching YouTube for for Celestial Navigation Made Easy by Tippecanoe Boats) along with your choice of textbook. You could then use the Navathome course, or similar, mostly as a way to check your answers to the RYA exercises and to sit the written paper.

 

[zoidberg]

....we were invited by one of the course members, to sample his sloe gin. He had unusual glasses that never seemed to empty. On my way home I commented "traffics busy tonight". "There isn't any "she said. I had read the cats eyes as on-coming head lights.

Worth remembering this lesson when preparing for a Round of Stars before dawn....

 

[Wing Mark]

I've got many of the books.

• Mary Blewitt is good but brief.
• I found Langley Price and Ouvry to be unpenetrable*
• ......

* Excerpt of text from Langley Price and Ouvry. This is on Page 8 - so it's part of their introduction to celestial navigation.
"The angle subtended at P (the elevated pole) between PZ (the observer's meridian) and PX (the star's meridian) is the local hour angle (LHA of the star. "

That's the whole thing about astro.
The above sentence is pretty clear, once you are fluent with using all the terms correctly.
If you're not comfortable with words like 'subtended', and you don't have a concrete correct definition of 'meridian' in your head, it's all gibberish.

It also seems incomplete, as such an angle needs to be considered as either positive or negative, which I recall is where most people made most errors with various quaintly named angles and corrections?

 

[capnsensible]

Based on people I've spoken to I suspect you're in the main correct but I find it a little surprising that these days when there's no actual *need* to learn astro people who do bother then do the bare minimum. 30+ years ago when it was a necessity for most small boat ocean sailors yes I see the motivation for only doing the bare minimum but now surely it's an "enthusiast" thing so why would one want to just get by with sun sights?

On the star-spotting front, on an ocean passage it doesn't take long to learn what your first rising stars are and where they'll appear. A few days in everything becomes much easier as a consequence. There's not really that much else to do on night watch on an ocean passage other than stare at the sky: I take my little colins gem book of the night sky with me. While my ability to name the constellations and brighter stars varies, after 3 weeks at sea it's usually pretty good.

For large numbers of people in the boating biz it's compulsory for advancement. Have a look at Master 200, Chief mate 3000 etc.
Lots of fast track guys n girls aspire to this and there are shedloads of superyachts around.....plus many other commercial vessels that require mca qualified skippers.

Then there are people eho want to do it coz they are planning an ocean passage and want to learn and practice a new skill.i got three of them sat in front of me right now slaving over hot sight reductions! Exam time. !!!

 

[zoidberg]

It's not just the 'exam time' ability to Reduce a sun sight on a Proforma, but rather the real-world ability to use that 'navigation information' in a continuous process of 'Where T F Are We?' and 'Where Are We Going Next?'

That's what navigators are for.

 

[capnsensible]

Navigators aren't born, they taught.

 

[zoidberg]

Unless you are so bored on a moony night you want to reduce a star that you actually recognise.... Cue some old master mariner telling us how they did it with a bit of papyrus and two sharpened match sticks.

Or learn some 'Polynesian Majik' and memorise some 'Home Stars' and 'Star Paths'.....

 

[zoidberg]

Navigators aren't born, they taught.

Aye, that. But that requires teachers... real teachers who practice the rare skill of getting inside a student's incomprehension and crafting a bespoke 'mental image' that works for that individual. Then doing that again with others, as often as is needed, until they can run on themselves.

 

[Graham_Wright]

Navigators aren't born, they taught.

they're? (and they).

 

[zoidberg]

AP3270, Vol 3, is the Table for selected navigational stars.... No need to know their name, just set sextant altitude, turn to azimuth during the twighlight observation period and, as if by magic, the little bugger should appear in the telescope (providing it has decent optics) ?

That's 'zackly how our V-Force was set up to operate. Two periscopic sextants on the Vulcan, precomputed Altitude and Azimuth, one Selected Star on the beam and another ahead or astern. Continuous fixing 'Along' and 'Across'..... And no concern for twilight period, for above 40,000 feet the sky is always dark enough.

Astronav and an in-built sextant has been used 'in anger' to bring the explosion-crippled Apollo 13 back safely. Not just theory....
navigating-by-earths-terminator

Oh, and the 'Murricains and Russians used variants of the same process. Perhaps they still do. All our yesterdays....

 

[laika]

For large numbers of people in the boating biz it's compulsory for advancement. Have a look at Master 200, Chief mate 3000 etc.

I'm not sure if you misinterpreted my post which was not "why do people learn astro?" but, responding to skylark's points about most yachties only doing sun sights: if you're interested enough to learn astro, why then restrict yourself to sun sights? I understand it's the minimum for YM Ocean and some people just want the ticket for career reasons (which is probably what you're saying) so yes, I get why folks would do a couple of sun sights, do the exam then never touch a sextant again, but if you're interested enough to continue using a sextant for reasons other than passing an exam, why would you restrict yourself to sun sights when star sights are more rewarding to do?

Unless there are preppers who distrust this whole satellite malarky