Guess what question I sometimes ask YM candidates.

[Beneteau381]

A problem s that now charts, or their electronic versions, for commercial vessels have different specifications to the ones we want. Our needs are not much different to that of Bass and Flinders (or Cook) but we are not a reliable source of revenue (in fact we all want it for free - or as a right). If bits of the world change, Bajansailor's reef, who cares (commercially)? Most commercial vessels are now large and our yachts are the same size, or some of them, as those of Cook who did much of their surveys of interest to us in 'big tenders'. Maersk are not going to pay for charts derived from 'big tenders'.

Different demands need different solutions

Jonathan

Charts arent free, WE pay/paid for them to be surveyed eventually by government. A point that the USA recognises and so the data is free from them. The UK gov and Oz? charge, a fact that tees people off? So we ARE a reliable source of revenus through our taxes!

 

[Daydream believer]

I have only scanned all the comments above very briefly. The first question I would want answered, regardless of contours depths & dates etc is "Where the f..k am I ?"
I generally start worrying about the other stuff when I have some clues about what is nearest.

 

[john_morris_uk]

I have only scanned all the comments above very briefly. The first question I would want answered, regardless of contours depths & dates etc is "Where the f..k am I ?"
I generally start worrying about the other stuff when I have some clues about what is nearest.

Perhaps your question misses the point. We all know exactly where we are within a metre or two, but that’s only helpful if you know how that relates to the chart and how to interpret how accurately the chart represents reality.

 

[john_morris_uk]

Charts arent free, WE pay/paid for them to be surveyed eventually by government. A point that the USA recognises and so the data is free from them. The UK gov and Oz? charge, a fact that tees people off? So we ARE a reliable source of revenus through our taxes!

An old fallacy much beloved by those who want free data. If you can persuade the UK population that everyone should pay for surveys through general taxation so that a few yotties can have free charts…. It’s not how it works in the UK. The UKHO has to balance its books as I understand things.
And that’s before we get started on the accuracy standards required and reliability of the data that UKJO jealously guard. (And rightly so IMHO). Compare to US charting data standards is chalk and cheese sometimes. But that’s another topic.

 

[Daydream believer]

Perhaps your question misses the point. We all know exactly where we are within a metre or two, but that’s only helpful if you know how that relates to the chart and how to interpret how accurately the chart represents reality.

Assuming you have the GPS on & it is working. I often do not bother & on one occasion a Lorenz chart plotter (now in the bin) froze & whilst I thought I was in deep water, I was actually sailing to rocks. Coming away from Roscoff en route to Guernsey. I would not have done if I had not been lazy.
I often get "lost" but I can still find my way round without GPS or phone etc

 

[john_morris_uk]

Assuming you have the GPS on & it is working. I often do not bother & on one occasion a Lorenz chart plotter (now in the bin) froze & whilst I thought I was in deep water, I was actually sailing to rocks. Coming away from Roscoff en route to Guernsey. I would not have done if I had not been lazy.
I often get "lost" but I can still find my way round without GPS or phone etc

Quite. Some of us learned our nav pre Decca and GPS. Old habits of being sceptical of our position die hard.

 

[arc1]

Very useful and reliable. The alarm makes tea, steers, passage plans and takes lines when we moor up. Regrettably, the bowline tying is a bit suspect, she blames it on being left handed.

I have a more advanced model that also has a heel angle alarm to let me know we should have reefed earlier...

 

[Beneteau381]

An old fallacy much beloved by those who want free data. If you can persuade the UK population that everyone should pay for surveys through general taxation so that a few yotties can have free charts…. It’s not how it works in the UK. The UKHO has to balance its books as I understand things.
And that’s before we get started on the accuracy standards required and reliability of the data that UKJO jealously guard. (And rightly so IMHO). Compare to US charting data standards is chalk and cheese sometimes. But that’s another topic.

Fallacy? Really? And how pray is the UKHO funded? Perhaps a little research?

 

[NormanS]

On the West Coast of Scotland there are still places where the "best" chart is 1:200,000. A fine pencil line equates to about one cable. Many of our old charts were leadline surveys, so can't be taken as gospel. The increasing use of quite large fish farm vessels in areas off the beaten track, had led to several groundings. There are areas which are shown as "Unsurveyed".
I was sailing around in Prince William Sound, Alaska, 25 years after the huge earthquake and tsunami, which wiped out several settlements. The area had not been resurveyed in detail, but the chart had various general warnings of "Bottom Uplift", varying from small amounts to up to 25ft. This made choosing anchorages quite challenging. A 25 foot difference is a huge difference!

 

[Chiara’s slave]

I have a more advanced model that also has a heel angle alarm to let me know we should have reefed earlier...

Obviously that functionality is disabled in hardware in my model. The motion sensors are often set off if the log goes over about 15kn though, which comes to much the same thing.

 

[Beneteau381]

An old fallacy much beloved by those who want free data. If you can persuade the UK population that everyone should pay for surveys through general taxation so that a few yotties can have free charts…. It’s not how it works in the UK. The UKHO has to balance its books as I understand things.
And that’s before we get started on the accuracy standards required and reliability of the data that UKJO jealously guard. (And rightly so IMHO). Compare to US charting data standards is chalk and cheese sometimes. But that’s another topic.

A little research brings up this "funded entirely from sales of hydrographic products and services to defence........."
https://assets.publishing.service.g...UKHO_Framework_Document_-_FINAL_Formatted.pdf
So who pays for "Defence"? Give the man a coconut US, the taxpayers!

 

[john_morris_uk]

Fallacy? Really? And how pray is the UKHO funded? Perhaps a little research?

I think you need to do the research. It’s a mixture of Gov taxation and income and if you want to change the ratio to more Gov taxation proportion then you try to persuade Gov and the UK population to cough up.
In fact it’s a bit more complex than that as the Gov pays for survey data that isn’t shared generally as it has military significance so it’s not a simple matter.

 

[john_morris_uk]

A little research brings up this "funded entirely from sales of hydrographic products and services to defence........."
https://assets.publishing.service.g...UKHO_Framework_Document_-_FINAL_Formatted.pdf
So who pays for "Defence"? Give the man a coconut US, the taxpayers!

Which bit of “Sales” as a source of income isn’t obvious? In fact UKHO is one of only two sources for world wide charting IIRC. The charting is sold to shipping all over the world.

 

[LittleSister]

I have only scanned all the comments above very briefly. The first question I would want answered, regardless of contours depths & dates etc is "Where the f..k am I ?"
I generally start worrying about the other stuff when I have some clues about what is nearest.

I see it rather differently (though suspect you and I probably differ little in practice).

This likely stems from my having started navigating before electronic aids were available to me, but also from having done a lot of research and thinking about mapping, its history, and how it represents and informs our world view rather than directly relates to 'reality'. Oh, and also me being a scaredy cat!

The starting point for me is (at least in principle) not 'Where am I?', nor the chart, but what do I make of what's around the boat from what I can see and feel, and my general understanding of the locality (e.g. muddy coast vs. rocky coast vs. offshore deep water). Only then do I add the clues I can glean from charts, plotter, pilot book. I see those as a guide to reality, rather than a direct reflection of reality.

How much reliance I place on those outside sources of clues will depend on a range of factors, of which the age of them (including survey date) and how confident I am in knowing where I am in relation to them (by GPS and/orother means).

I have, on a number of occasions over the years, found I was not quite where I thought I was, more often found that what I thought I was looking at was actually something else, or otherwise just been momentarily confused/mistaken about something. So my starting point is a degree of disbelief: I am almost always sceptical about exactly where I am, where I am in relation to charts and other 'information' (which is something different), how reliable that information is (bearing in mind clues such as date/method of survey and how likely changes are to the bottom and other objects).

For a variety of reasons (not least lack of money) I habitually sail with out of date charts (paper and plotter). I rarely find that a problem, because I'm only using them as a guide - one source of information - and compare that to what I can see or otherwise detect. I'm not expecting reality to necessarily conform to it.

A lot of the time locational exactitude is not important. I mainly sail in coastal waters where, as Tom Cunliffe wisely observed, for most of the time you don't need to know where you are, just where you're not! Offshore, most of the time you won't need to know exactly where you are for hours, or even days, yet.

I try to avoid being completely dependent on 'outside' information (e.g.navigating between unseen rocks depending on the chart and GPS), though admit I have taken that chance on occasion.

It shocks me that there are many people out there that are unaware of, and uninterested in, the uncertainties and unreliabilities of mapping and digital information, etc., not only but especially in relation to boat navigation. I guess that marks me as an old fuddy-duddy.

On the bright side, most of them seem to manage to, er, sail through life and boat voyages in blissful ignorance of the uncertainties hidden by the digits and shapes on their screens without coming a cropper.

That won't get them through their YM Exam under the beady eyes of John M, though!

Guess what question I sometimes ask YM candidates.

Whose turn is it to put the kettle on?

 

[dunedin]

Fallacy? Really? And how pray is the UKHO funded? Perhaps a little research?

As John Morris already stated, the UK Government requires UKHO to be self funded from the sales of its products - charts, paper and electronic, and navigational books.
As most money likely comes from large ships, that is where they invest in surveys

 

[dunedin]

Here’s your only clue.
View attachment 151425

One of the big issues with all leisure craft electronic vector charts (Navionics, C-Map, Lighthouse etc), as far as I know, is that it is impossible to get on screen these details of the chart sources - or Categories of Zones of Confidence (CATZOC) in chart maker speak.
Hence when you zoom in it shows nice comforting detail, but doesn’t allow you to find out that the “detail” may in fact have been done by somebody in a rowing boat over 100 years ago. This applies to a LOT of the more remote UK waters - indeed there are patches still listed as “unsurveyed” even on busy yachting routes like the coast of Skye, less than 15 miles from Mallaig.
And before somebody says it doesn’t matter, and the people surveying in rowing boats were very skilled - they were very skilled, but they surveyed in lines, but lacked side sonar so between two survey lines showing 10m there could (and often is) a rock pinnacle just below the surface.
PS. Being able to interrogate, or better still highlight on the chart in some way, the CATZOC data is one of the things that people like RIN and Cruising a Association are pressing leisure chart suppliers to add to their software before paper (and associated raster) charts can be withdrawn entirely.

 

[mattonthesea]

Very useful and reliable. The alarm makes tea, steers, passage plans and takes lines when we moor up. Regrettably, the bowline tying is a bit suspect, she blames it on being left handed.

My alarm will inform me quite persistently that the chart plotter is turned off; it was converted to marine function post paper reliance.

I must add that the alarm is one small facet of a wonderful sailing companion.

 

[benjenbav]

By looking at the source data we can see that inshore the source is a leadline survey dating from 1858/60, further out it is 'f' - misc data and passage soundings.
So imperfectly surveyed - hence the broken contour lines.
I reckon Benjenbav at #2 should get the prize.

Re metric or fathoms. Admiralty ' fathoms' charts had grey land. Metres have yellow land.

Trap for young players - I have some US copies (rasters) of Chilean charts from the early 70's with grey land and soundings in metres. Was a bit confused at first - had to check the title block. Sample is from Ocpn display.

Too kind!

 

[Beneteau381]

I think you need to do the research. It’s a mixture of Gov taxation and income and if you want to change the ratio to more Gov taxation proportion then you try to persuade Gov and the UK population to cough up.
In fact it’s a bit more complex than that as the Gov pays for survey data that isn’t shared generally as it has military significance so it’s not a simple matter.

So John, the quick "its a fallacy" isnt quite right. Your answer accepts my argument, our taxes are payin the majority, the same as the US, so why do we pay twice, unlike the US

 

[Beneteau381]

As John Morris already stated, the UK Government requires UKHO to be self funded from the sales of its products - charts, paper and electronic, and navigational books.
As most money likely comes from large ships, that is where they invest in surveys

But my argument is that the taxpayer already pays for it via the armed forces which we pay for throughour taxes.