Don't throw away your paper charts...

DeeGee

Well-Known Member
Joined
11 Feb 2003
Messages
1,663
Location
North Brittany.
Visit site
Don\'t throw away your paper charts...

Ne jetez pas vos cartes papier! Voiles et Voiliers has an in-depth (5 pages) look at vector charting packages, in the light of French skippers (non-commercial) no longer needing paper charts, as long as they have electronic equivalents aboard. (Surprising in the light of their stringent safety regs - which are more or less the same as charter coding your yacht – for offshore use).

They looked at CMap, Navionics, Garmin. They were not looking at software, like MaxSea, Seapro… which use the data produced by the vector packages.

They took a look at the screen data produced by each of the products, at different scales, for the 'Rade de Toulon' and 'Abords de la Rochelle'. The article illustrates with screenshots of the various outputs, at different scales, and a print of the relevant paper chart. The screenshots show navy mooring buoys missing, lights out of place or missing.. devastating, really. Buoys which were in place were sometimes misleadingly shown as towers, instead of normal buoys. Whole breakwaters in La Rochelle were missing on CMap and Navionics.

[Note, I have no axe to grind – I am using CMap, and, yes, I have noticed a few errors on lights, but I always use a paper chart as primary data, NOT CMap].

Their summary, or my rather good translation of it…

A Dismaying Assessment
By the screen captures, one can only be frightened by the errors and omissions. The Italian fabricators of the vector charts defend themselves by saying their products should only be used with those dictated by the regulations.
For ever, in France, the marine paper charts were obligatory aboard pleasure craft, which were provided by SHOM, UKHO or all other official chart organisations. From now on this new situation, which frees the skipper from all apprenticeship of the art of navigation (the advent of GPS was a major stage), can choose at leisure amongst the positioning systems (vector or raster charts)….
The three cartographies which we have tested and which can be read on the dedicated plotters, show themselves finally to be bad fellow-travellers… Unahappily, regulation imposes no constraints of accuracy on these cartographies and lets SHOM battle in order to enforce its fundamental rights. In brief, if you have to choose between one of these three systems, Garmin has our favour, because it is the only one to reference itself openly to the official charts, whilst CMap, and worse still, Navionics, literally make fun of the skipper in proposing products full of gross errors or missing some most elementary information. And we haven’t even talked ot the price!”

A sidebar in the article I lazily just stuck through Babel Fish:
With ARCS (charts of British Admiralty), the SHOM is one of the hydrographic services more reputes in the world. Since 1984, debuts of Navionics and C-Map, the charts of the SHOM are used by them as reference and on the same basis the English charts or etran-geres. But two Italian manufacturers extremely the deaf person ear since years when the SHOM them reclame of the royalties for use of the intellectual property. Today, C-Map and Navionics have sign no agreement, and only Garmin pays relative royalties has the use of the French cartographic. It is one of the reasons why the electronic cartographic Garmin avere nearest to the official paper charts of SHOM.
 
Re: Don\'t throw away your paper charts...

Very disturbing, but also explains why I observed many chart issues on our summer cruise to La Rochelle. The worst were the charts for harbours and ports, where I found that I was either sailing over land, or would have two charts superimposed on each other but not in alignment. I put the latter issue down to the fact that differents parts of harbours were converted at different zoom ratios.

I find that keeping paper backup charts to the right detail is prohibitively expensive, so end up relying on the electronic ones even with their faults.
 
Re: Don\'t throw away your paper charts...

Have the paper charts and primarily use them. I find it difficult to plan pilotage otherwise
 
Re: Don\'t throw away your paper charts...

Beware! the paper ones (even updated) have faults as well sometimes. Imray transpose manually from Admiralty charts and it has been known (2000 North coast of Spain) for lights to go on the wrong headlands and not be [icked up by the proof readers.
 
Re: Don\'t throw away your paper charts...

To err is human; it takes a computer to really mess things up!

We should be aware of the shortcomings of all the navigational aids we use. Most of us are well aware of the problems with electronics and this thread is a timely reminder that there are problems with conventional charts as well.

(Oh, and by the way, you can't always trust correction notices either. In recent years I've alerted one chart publisher to two correction notices which required correction.)
 
Re: Don\'t throw away your paper charts...

I'm a big fan of Voiles et Voileurs but I wonder just a tad about a couple of comments on this but then don't have the entire article to put everything into context.

Like you I use C-Map. On mine I can chose if I wish to display the chart boundaries of the screen I am looking at and just by placing the cursur inside a boundary and clicking enter it gives all the information about the source of original chart used and the date updated. I am therefore surprised that V et V were apparently unaware of this feature.

As far as 'missing data' is concerned I am sure there may be other factors involved that may not make for quite such good journalism, equally there will always be human error on either paper or electronic charts. For example, in the case of missing Navy buoys, were these in place when the original paper chart was produced or the electronic one created from it? Assuming they really were there then it may be that for simplicity (ie reduced clutter) these have not been reproduced on the electronic chart at ALL scale levels but may be there if zooming in to a larger scale chart. Such a larger scale chart is very probably included in the electronic cartridge but how many will have the same ultra large scale in paper form, I know I don't.

Another point is that I wonder how many realise how long it takes in practice to get corrections published even for the basic paper chart? From those I have been aware of in our local area there is often a delay of up to 12 months and on occasion I have even seen a subsequent change having been made before even the first one was out in the open! It just goes to say that we live in a rapidly changing world as far as nav aids are concerned so whatever the source a little care is required. The good thing however, at least for those of us not in areas of large shifting sandbanks etc, is that the solid bits generally don't move!

BTW having recently revisited Treguier and with the plotter recording our actual groundtrack up the river (C-Map) it showed our track crossing drying areas in several places on the large scale chart but on a smaller scale (but similar to a paper chart harbour plan scale) it was in the blue bits. This does highlight one of the advantages of a plotter as I'm sure you know, that once you have been there and recorded a safe track dead centre channel, you can set up WPTS on it you can trust or even 'save' the track line and follow it next time, this eliminates the charting or datum errors and with current GPS accuracy is pretty good.

Like you we have also a Yeoman to plot on paper charts. However, much as I rate Yeoman very highly it would IMO be a very poor substitute to a plotter entering Treguier for example a) because I would not have a similar large scale (huge scale) paper chart let alone one referenced to Yeoman and b) because Yeoman doesn't have a continuous position and doesn't show where you have been except at times of plotting, nor does it show your current heading as well as COG and even it's projection.

Robin
 
Reply to Robin

Yes, with my CMap, I can call up the source of data for the chart I am using. They say that they are SHOM xxxx, with digitisation date and last Notice to Mariners application date. (For me, FWIW, around La Rochelle, this was 7413,DD:23/09/03, NM:20/03/04). I dont think that this was an issue in V&V, they knew that the data came from SHOM, that was a major thread of their article - the other was the fact that so many errors were made in the digitisation.

I expect any charting I use, paper or electronic, to be up-to-date as the day I buy it. I suspect these navy buoys have been there for some time. They do come up on the Navionics, but entirely misplaced, and only one shown.

I didn't write the article; it is a pity such an article (written apparently with no worry about losing advertising, etc) could not appear in YM or PBO. I just felt it worth mentioning, and perhaps peeps can find a copy if they feel it is worth reading. It was pretty damning, I may not have conveyed properly the tone.

On the other hand, speaking personally, I think this is a case of a moving target, and that the vector versions can only get better - I have looked at my CMap data for La Rochelle (I dont have Rade de Toulon), and find that mine appears to be more up to date than shown in the article. A further factor is that the data is used by a host package, whether it is a dedicated plotter, or a PC. That host can show/hide as much data as it is programmed to do. If the host is hiding data, I am not sure if V&V took it into account. And was the CMap data they were using coming from an old chip? When CMap seamlessly switches to another chart (as you scale up/down), are V&V comparing data from the right SHOM.

In other words, the article can't tell the whole story, but it is a good reminder that you should NOT throw away your paper charts (yet).

(Edited) I forgot to address your comments on Yeoman. When I am entering an unknown estuary like Treguier was once, I DO have the large-scale paper chart - and, yes, it is expensive - but do not understand your comments 'let alone one referenced..', it takes me about 1 minute to mark up a chart for later use with Yeoman, including entering it into Yeomans 500 chart user-library. Having marked a position on the chart, I have a continuous record of track. COG and heading etc I read off the GPS. I also have all my nav data repeated on my Nav6, which tells me stuff like set and drift of the tide, direction and strength of the wind. If you have these on your plotter, then it is a good one, but for me, I prefer them presented separately.
 
Re: Don\'t throw away your paper charts...

At last a post which I believe justifies my preference for using raster electronic charts sourced form the UK Admiralty and SHOM paper charts.... /forums/images/graemlins/laugh.gif
 
Re: Don\'t throw away your paper charts...

[ QUOTE ]
At last a post which I believe justifies my preference for using raster electronic charts sourced form the UK Admiralty and SHOM paper charts.... /forums/images/graemlins/laugh.gif

[/ QUOTE ]Yes, the article studiously avoids raster. I used to scan my paper charts in, and use them in a plotting package (excellent one) - OziExplorer, you can guess where it was created - and felt quite happy with that solution. In time, I found that it was impractical when I was living on the boat, so switched to proprietary package MaxSea, using CMap. I was surprised by both how good these packages are in many ways, but in how poor the image is in comparison with raster.
 
Re: Don\'t throw away your paper charts...

Whenever I talk about my paper charts and Yeoman plotter I get the feeling I'm a bit of a Luddite.

MMM, not so sure though.
 
As an Ex Ships navigator ...

I worked for years with NOAA / UKHO / other Countries charts ... so got used to the style and character. I missed the old fathom charts ..... they had character and style that is sadly missed ....

I now use PC based plotting as well as paper charts on my boat ... and to be honest rarely venture out a paper chart ...

I use Seaclear and also where possible Vector based ... I have got to like the uncluttered Vector chart where text doesn't expand contract with zoom etc. - like a raster does .. I also like the ability to decide how much detail is to be shown ..which Raster again fails on ....

Raster has a feel that agrees with wanting to see a paper chart ... but once you start zooming around etc. you soon find out the limitations ....

IMHO of course !!
 
Re: Reply to Robin

[ QUOTE ]
Garmin has our favour, because it is the only one to reference itself openly to the official charts,

[/ QUOTE ]

This was why I commented that C-Map DO show the source and date of the base chart, which you agree with I see.

[ QUOTE ]
I forgot to address your comments on Yeoman. When I am entering an unknown estuary like Treguier was once, I DO have the large-scale paper chart - and, yes, it is expensive - but do not understand your comments 'let alone one referenced..', it takes me about 1 minute to mark up a chart for later use with Yeoman, including entering it into Yeomans 500 chart user-library. Having marked a position on the chart, I have a continuous record of track. COG and heading etc I read off the GPS. I also have all my nav data repeated on my Nav6, which tells me stuff like set and drift of the tide, direction and strength of the wind. If you have these on your plotter, then it is a good one, but for me, I prefer them presented separately.

[/ QUOTE ]


Don't get me wrong, I have a Yeoman and have used one almost since they first came out, so count me as a fan. My point however was that like most people I don't carry ultra large harbour charts of every harbour although I may well have them for some (as you do for Treguier). I use Imray paper charts for Brittany and they have pretty good harbour charts as insets, and some of these insets I have referenced into the Yeoman as separate charts. However these plans are still small scale by comparison to the enormous detail charts included with the C-Map cartridge I use. As for entering Treguier, I have a plotter in the cockpit as well as below so can see the continuous plot of our position blinking away as we follow the channel and the recorded trackline of where we have already been. The 'blinking boat' position symbol shows which way we are going (COG) with an extended dotted line projecting ahead to show where we will go if we continue on that heading. I could nip up and down 'n' times to the Yeoman at the chart table and plot a position but prefer to be in the cockpit watching what and where we are and with confirmation from the plotter instantly available. In practice then the paper chart whilst available is only there as a fallback, and especially so now I have 'tweaked' a few wpts onto the actual track. We too have all the Navdata in the cockpit both via a ST50 Navdata repeater amongst others at the wheel and the data screen on our cockpit plotter which is set to show BTW/DTW/COG/SOG/VMG to wpt/TTG to wpt.

I think in practice we both agree and Yes I do and will continue to keep a full set of charts and referenced to the Yeoman. I still think the plotter is superb and it (with Mk1 eyeball) is the first choice.

Robin
 
Re: As an Ex Ships navigator ...

Well, I'm a bit of an electronic chart tart. We have a C-map chartplotter and an ARCS based Navmaster PC on the chart table. Find the PC good for planning and overview and the chartplotter good for final approaches.

Agree with most of above, if I was going to somewhere with lots of submerged rocks like the channel islands or NW France, I'd use the plotter with some caution. Where we are in Norway 'tis no prob 'cos you are either in hundreds of meters or ashore most of the time, so rely upon the plotter to see us into strange harbours, using a degree of commonsense of course, trying to reconcile what we see with the mark one eyeball with what the plotter is displaying.
 
Re: Reply to Robin

Oooo, we agree and disagree.

For inshore nav, I rarely use any chart in real-time, I have what I grandiosely call 'pilot's notes' - list of marks, transits and notes, which is what I use for the actual eyeball stuff, just because, as someone mentioned, I do not like navigating over apparently dry land !! I don't steer to waypoints when eyeball nav is appropriate. There is nothing I like better than sailing/motoring to a transit in a gross cross-current or the satisfaction of picking up the next mark with the binoculars where the handheld compass tells me it should be.

My nav apprenticeship was done in the Thames estuary, where reliance on pre-recorded waypoints would have done me a doodoo.

Anyway,now that the season is coming to an end (?), we can expect more interesting discussions here, with peeps not off sailing, hey?
 
Top