Fake charts: really a safety risk, or just a copyright issue?

Well, as I don't use paper charts (scandalised whispers off net) The question is of purely academic interest.
I'd suggest the reproduction inaccuracies are of little significance, that Droggie is a foolish dog-in-the-manger (all his info is available free through the US agency).
If one doesn't find innumerable detail changes in ALL charts you're either very unobservant or living in a fools' paradise.
The "best" chart I ever had was a 1873 printing of Brittany, better than SHOM or later Admiralty charts. Rocks tend to not move around, buoys and lights, like all things human, are fallible.
 
LadyInBed said:
People have been using copies of charts for decades.
Chart stitching software such as http://www.oziexplorer.com has been used for producing electronic analog charts for use in its own SW or with OpenCPN or the like for almost as long as I can remember.
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Copying for your personal use is OK, within reason, as long as you own the chart. What is not legal is copying for commercial gain.
 
JumbleDuck said:
The CCC pilots used to recommend photocopying out-of-copyright fathoms charts at the National Library of Scotland as they were (are?) more detailed than the current metric ones.
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They would have to be more than 70 years old to be legal for copying, AFAIR. May well be useful off the West Coast, though, if the most recent survey was in the 19th century.
 
AntarcticPilot said:
They would have to be more than 70 years old to be legal for copying, AFAIR. May well be useful off the West Coast, though, if the most recent survey was in the 19th century.
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Yup. I don't think the NLS will let you copy more recent charts. I have a few old fathoms charts of the West Coast and they generally have a LOT more soundings on them than the modern ones do.
 
JumbleDuck said:
Yup. I don't think the NLS will let you copy more recent charts. I have a few old fathoms charts of the West Coast and they generally have a LOT more soundings on them than the modern ones do.
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Worth bearing in mind that those soundings are much less precisely located than those from a modern survey, except close inshore. Also, a chart based on a modern survey will have been drawn using FAR more soundings than one based on a 19th century survey. If there are a lot of soundings available, the procedure is to use all of them to draw contours, but only use a selection of soundings on the chart to give a representative view of the shape of the bottom.

There are issues to do with sampling; soundings tend to be densely distributed along a track, but the track spacing is much wider than the spacing between soundings along track. This causes problems with contouring (sausage strings along tracks is the usual symptom). Not a problem with swath bathymetry, but that is usually only feasible in deeper water.
 
AntarcticPilot said:
Worth bearing in mind that those soundings are much less precisely located than those from a modern survey, except close inshore.
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True, but I think they were making the suggestion for inshore use. I suspect that the navy was more worried about getting small boats in and out of places than they are nowadays. Your comments on contours brings back happy memories of plotting stress contours in the research days of my youth.

As a matter of interest, are the spot depths on modern charts actual soundings, or are they interpolated depths to give a fair spread, or a mixture?
 
JumbleDuck said:
True, but I think they were making the suggestion for inshore use. I suspect that the navy was more worried about getting small boats in and out of places than they are nowadays. Your comments on contours brings back happy memories of plotting stress contours in the research days of my youth.

As a matter of interest, are the spot depths on modern charts actual soundings, or are they interpolated depths to give a fair spread, or a mixture?
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As far as I know, they are actual soundings - that would certainly be best practice. Interpolated depths might well be wrong - isolated rocks or such would muck up the interpolation nicely!
 
AntarcticPilot said:
As far as I know, they are actual soundings - that would certainly be best practice. Interpolated depths might well be wrong - isolated rocks or such would muck up the interpolation nicely!
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Thanks. On on the old leadline survey charts you can often see the tracks along which the soundings were taken, and the modern scattered ones are very different. I presume they have lots and choose 'em at a useful spacing.
 
There are vast areas in Scottish waters where the last surveys were done in the 1850s and 1860s. There are also several areas where the best Admiralty Chart is at a scale of 1:200,000. At that scale, a fine pencil line is about a cable wide.
I don't think any slight potential inaccuracy from using a copy of such a chart, would make the slightest difference.
 
I wonder how many of us actually use updated or up to date charts? And how many actually use paper charts at all these days. Then amongst those who use electronic charts, how many use the freely available but pirated CM93 world charts on a lappy?

I cant help but think that the question of pirated charts is irrelevant to most of us . Writing personally, I cant remember the last time that I went close enough to a hazard to be worried about the progeny of my charts, but when I do so then I would make sure that I had the right data. Instead, most of the time I give solid hazards a good offing and never rely on lights. Or to put it another way, if you stripped out of an admiralty chart all the things that are irrelevant to a modern gps guiede yottie, there would be very little if anything marked more than a few metres offshore with well buoyed channels into the shore berths we mostly use.

I reckon I could safely navigate from Falmouth to Cherbourg with nothing more than an old fashioned gps and a destination lat and long. Entrance and exit using the well marked channels. I'm less sure that I could do something similar on the scottish west coast but not convinced.

I hasten to add that I dont navigate without charts by the way
 
JumbleDuck said:
Thanks. On on the old leadline survey charts you can often see the tracks along which the soundings were taken, and the modern scattered ones are very different. I presume they have lots and choose 'em at a useful spacing.
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I've seen the original data for a few surveys carried out in the last decade. Usually done for by wind farm companies or ports that are having dredging done. They're just the same, except the survey vessel might go back and forth a bit more, you can still see its track.
 
birdseye said:
I reckon I could safely navigate from Falmouth to Cherbourg with nothing more than an old fashioned gps and a destination lat and long. Entrance and exit using the well marked channels. I'm less sure that I could do something similar on the scottish west coast but not convinced.
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Lots of the west coast is quite safe to do by eyeball. There is practically nowhere in the Firth of Clyde that a chart is actually needed, though even twenty five years since I first went through I still have one out for the Burnt Isles in the Kyles of Bute. Out in the hairy bits they are a lot more useful, though more for anchorages than avoiding things, since the things which need avoiding are generally large and made of stone by either (a) God or (b) the Stevenson family.
 
JumbleDuck said:
Lots of the west coast is quite safe to do by eyeball. There is practically nowhere in the Firth of Clyde that a chart is actually needed, though even twenty five years since I first went through I still have one out for the Burnt Isles in the Kyles of Bute. Out in the hairy bits they are a lot more useful, though more for anchorages than avoiding things, since the things which need avoiding are generally large and made of stone by either (a) God or (b) the Stevenson family.
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Might I suggest to you, and those others who "navigate" without the benefit of charted information, that you head out through the Sound of Harris, and then turn down to the Monachs. Could be challenging.

Ah! Yes, eyeball. I used to know someone who navigated on the "See Water" principle. Unfortunately he had some mishaps with rocks, which were lurking under the surface.
 
NormanS said:
Might I suggest to you, and those others who "navigate" without the benefit of charted information, that you head out through the Sound of Harris, and then turn down to the Monachs. Could be challenging.
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Was there some bit of "Lots of the west coast" and "Out in the hairy bits they are a lot more useful" which was particularly confusing? I carry a modest collection of charts on board: about fifty full-sized admiralty, five leisure portfolios and a complete set for the western side of Britain on my tablet, just for luck. I also have a current Antares subscription.

There are lots of places where charts are essential, but they are are often places which it's quite easy to avoid if you want to.
 
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Wooden Boat Fittings said:
Ah, Droggy. Droggy is the Hydrographer of the Navy, he under whose name all Admiralty charts are issued. It rather suits him, don't you think?
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Nope, still not getting it. The current Hydrographer of the Navy is (according to Wikipedia) Captain David Robertson however the post has not been associated with the UKHO since 2001 so he nothing to do with the issuance of charts etc

Is this a piece of naval slang or summat???? :)
 
Erbas said:
Nope, still not getting it. The current Hydrographer of the Navy is (according to Wikipedia) Captain David Robertson however the post has not been associated with the UKHO since 2001 so he nothing to do with the issuance of charts etc

Is this a piece of naval slang or summat???? :)
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Perhaps "Droggy" is naval slang for "hyDROGrapher".
 
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