Paper Charts or Just Electronic

[Dockhead]

Originally Posted by requiem

The Vestas example is interesting because the C-map charts they had didn't display the Shoals at several zoom levels. There were hints that even more detailed charts should be looked at (which then goes to the user), but the accident report noted that the land and reef were displayed on all scales of paper charts reviewed. Ironically, the default world chart in the boat's chartplotter did include the Shoals, but that MFD was used mainly for AIS in busier areas and apparently not being observed.

It's worth reviewing the report as it calls out differences in software packages that might not be expected by users (e.g. not showing detailed data if you zoomed in on one area and then panned into a different region).

But that is well known and universal -- small plotters using vector charts necessarily must wipe out detail when you zoom out -- otherwise the screen would be so cluttered you couldn't understand anything. This is by design. Paper charts are capable of showing much greater detail even at small scales because -- duh -- they are much bigger than a 7" plotter screen. So they do.


Besides that, paper charts are produced with at least some intervention by a human cartographer who decides which details to include in which particular chart. Vector chart views are produced "on the fly" by the plotter.


Anyone can see this if you take a paper chart of some area and then look at the same area on your plotter, and zoom in and out. You will see that it is necessary to zoom quite far in to see all of the significant detail, and when you do that, you can only look at a small area at a time.



So small boat chart plotters are just not really well suited for navigation -- they are for pilotage, rather, and they are fantastic tools for that.


I have more sympathy for the Vestas folks than most -- I hope I would not have made such a mistake, but there but for the grace of God go I . . .



Ocean sailing, and especially racing and applying tactics, you don't just follow a straight line -- a precalculated and thoroughly checked "route" -- like you might sailing coastally. When you are sailing hundreds or thousands of miles and sailing this way and that to optimize your tactics, you might cover potentially a large piece of ocean. Checking out such a large piece of ocean with a small plotter and vector charts is possible but is a bit of a fool's errand and I'm not sure it's so hard to screw up.


Paper charts avoid this issue -- of course you don't get ALL detail on the smaller scale charts, but the levels of zoom are very distinct and it is obvious when a chart is not detailed enough.



RASTER charts -- which are just electronic scans of paper charts -- have the same benefit, plus can be realistically stored and kept updated even if you sail a large cruising area. And can be automatically plotted on by OpenCPN or whatever program you use. I understand raster charts are expected to disappear, which will be a shame, but commercial vessels already mostly use vector charts and their charting system can be adjusted to provide the necessary detail on their large screens. We can do the same with OpenCPN and a sufficiently large screen.

[requiem]

Originally Posted by Dockhead

But that is well known and universal -- small plotters using vector charts necessarily must wipe out detail when you zoom out -- otherwise the screen would be so cluttered you couldn't understand anything. This is by design. Paper charts are capable of showing much greater detail even at small scales because -- duh -- they are much bigger than a 7" plotter screen. So they do.

Besides that, paper charts are produced with at least some intervention by a human cartographer who decides which details to include in which particular chart. Vector chart views are produced "on the fly" by the plotter.

Certainly this is expected; but the ENC charts also have human prioritization and this resulted in the particular charts the team was using not indicating danger at scales where they arguably should have; the navigator and skipper had reviewed the route, including zooming in on the Shoals a few times, but thought the only issue in the area was a minimum depth of 40 m. (Note that they were using laptops for navigation and not the plotter.)

[Tillsbury]

The other consideration is the resolution you’re using. My iPad Pro (resolution 2700x2000ish) displays raster charts beautifully as if they were printed. A “normal” e.g. raymarine a7 or a9 plotter screen at 840x480 simply cannot show anything like that detail, whether using vector or raster charts. I would only use that kind of resolution for approximate positioning. Detailed pilotage is done on the iPad, which is the same as using a paper chart for close-up work.

[Kenomac]

Originally Posted by Tillsbury

The other consideration is the resolution you’re using. My iPad Pro (resolution 2700x2000ish) displays raster charts beautifully as if they were printed. A “normal” e.g. raymarine a7 or a9 plotter screen at 840x480 simply cannot show anything like that detail, whether using vector or raster charts. I would only use that kind of resolution for approximate positioning. Detailed pilotage is done on the iPad, which is the same as using a paper chart for close-up work.

Do you have a waterproof case for your ipad pro? Is it the large screen? What make and model case? We use three ipad air 2 with lifeproof cases and thinking of upgrading one of them.

[GordMay]

I occasionally see some apparent confusion, regarding chart scales.
Chart Scale vs Chart Detail:
A chart that provides a lot of detail, for a small area, is a large scale chart.
A chart that covers a vast area, and provides little detail, is a small scale chart.
The larger the figure indicating the proportion of the scale, the smaller the scale of the chart. A harbour chart, with a scale of 1:10,000 is on a much larger scale, for instance, than a coastal chart, whose scale is 1:200,000.
Remember:
Large scale = Small Area, Great Detail
Small Scale = Large Area, Little Detail

[vikingwoman]

Never go anywhere without paper charts. Open CPN is fun but not reliable. Cruising guides and pilot books a must. Save money and buy a spare anchor.

[Perfect Ride]

OP: We live in a time when we have access to so many forms of information.

We carry as many forms of reliable unique charting as we can get our hands on. Differing uses warrant differing formats.

Paper charts come in many forms and sources, different applications and areas of the world dictate different and often multiple sources.

Electronic charts: We typically have 4 or more sources for an area until we learn what is most reliable for the various types of information needed.

Sat imagery: we carry many sets to maximize quality in all areas we are going to. Surface wind, sun angle, cloud can all deteriorate portions of an image set. Google Earth historical view (saved for off line use), MotionX GPShd and Ovital are good examples.

[sailorboy1]

Originally Posted by Brian2109

Just curious how many people still reference paper charts before sailing somewhere. It seems that the electronic charts are so reliable and paper charts would only be needed in rare circumstances. Just curious as I have just begun getting into sailing.

I still use paper charts for planning. Nothing to do with electronic being reliable, it's just that I can read the big charts easier than what is on a computer/phone/tablet screen and I can write on the charts.

Charts are cheap!!!!! I know somethings at the time buying a chartbook etc at $130 seems expensive, but that's CHEAP for what it is and its' importance.

[A CheeseHead]

As we approached Barbados in the night in a passage from Las Palmas and bound for Bridgetown, we held off until dawn, even though the electronic chart showed us to be well offshore. Why? Because the charted positions for many (most?) islands were 'located' using 19thC methods, and they may not be where the GPS says they are supposed to be (even though the boat IS where the GPS says it is). Reliance on e-charts to tell you where the water isn't is a sure & certain way to have your voyage end unpleasantly.

[nmccubbin]

Most sailors we meet cruising are 100% electronic. We have been for 11years, cruising about 6 months per year. About 30,000 miles
When wandering all over the place, buying paper charts would bankrupt us.
Today, the best cruising charts in many areas are amateur ones available only in electronic form

[a64pilot]

Originally Posted by jackdale

Check out the caption below this chartplotter on a Canadian Coast Guard cutter.

That is for the lawyers, whenever I installed a very expensive and exceptionally accurate GPS Nav system in an Ag Plane so that it could direct and often control the dispensing of chemicals, I had to placard it “Not to be used for Navigation” this was because there was no STC for that particular instrument.
It was ridiculous, cause what else could it have been used for, pilot entertainment?

However in this case, it makes sense, I believe it’s trying to say that you need to look outside every so often and not just drive the plotter

[ben2go]

You guys and your paper charts. I see no one has experienced the spontaneous chart combustion at 2 am in complete darkness during a force 10 gale. You have heat and light for about 15 seconds and then poof nothingness.


I'm kidding of course. I've never done any long range cruising. I still wouldn't leave the dock without updated charts of the areas I am planning to be in or go through. I would also want some surrounding charts as well in case I needed a backup plan for getting away from the weather. As good as electronics seem to be nowadays, I regularly hear of troubles with electronic nav systems. Maybe I'm old fashion but I see no substitute for paper and pencil.

[a64pilot]

Originally Posted by Kenomac

Someone who believes the chartplotter to always be correct in the night and has never been required to figure out drift on a paper chart.

Hint: Current can’t be seen at night.

But nice use of a big word, I’m so impressed.

It will however give you old positions, current position, heading and track.
A paper chart will give you none of that.
Cmon Ken, you or no one else plots their position on a paper chart every few minutes, to start with without electronics the position wouldn’t be as accurate.

The whole electronic vs paper chart thing is sort of silly, both can be the exact same chart, it’s presentation is the only difference, however the plotter gives you a whole lot more data.
It’s like arguing which is better, paper or plastic charts.

An electronic chart representation will not stop people from making mistakes, but neither will paper charts, people ran aground before the advent of electronic charts, and I’d say more often than they do now, cause now you have your position constantly updated and displayed in front of you, a chart on the table you don’t. The blind reliance of a chart doesn’t stop or end with how it’s represented.

You probably ought to drop the sarcasm, it doesn’t make you look smarter.

[Kenomac]

Originally Posted by Kenomac

One needs to have an understanding of how to use paper charts in order to understand when things aren’t going as planned.

Example: While rounding the north eastern channel of Corfu last evening at 2am while watching the chartplotter and radar, the boat began to drift towards the rocks in such a way as to overcome the auto pilots ability to compensate. I knew immediately current was the cause and took control.

Someone only knowing how to use an electronic chartplotter... might not have figured it out in time. Probably would have wasted valuable time screwing around with the chartplotter.

Originally Posted by a64pilot

It will however give you old positions, current position, heading and track.
A paper chart will give you none of that.
Cmon Ken, you or no one else plots their position on a paper chart every few minutes, to start with without electronics the position wouldn’t be as accurate.

The whole electronic vs paper chart thing is sort of silly, both can be the exact same chart, it’s presentation is the only difference, however the plotter gives you a whole lot more data.
It’s like arguing which is better, paper or plastic charts.

An electronic chart representation will not stop people from making mistakes, but neither will paper charts, people ran aground before the advent of electronic charts, and I’d say more often than they do now, cause now you have your position constantly updated and displayed in front of you, a chart on the table you don’t. The blind reliance of a chart doesn’t stop or end with how it’s represented.

You probably ought to drop the sarcasm, it doesn’t make you look smarter.

Please go back and read post #72, then you’ll realize that you were responding to a short answer explaining #72 and not the subject being discussed.

[Kenomac]

Originally Posted by Don C L

I think Ken meant that anyone who was only relying on a chartplotter may have missed it, but that since radar, and autopilot response to course change, were also being monitored, it allowed for the appropriate and more rapid course correction.
I'm not sure, is that correct Ken?

Originally Posted by Kenomac

Don,

Yes, thank you.

Plus add... many people who rely on only a chartplotter, would not understand current and it’s effect on a boat, so would not be equipped to understand why the boat was rapidly drifting off course at night, and I dare say might panic. Having plotted on paper over the years, current and having to adjust manually for current is not something easily forgotten.

Many on this forum just like to argue these days. thanks for being someone who likes to help out.

And for those who like to argue... there was no time to sit down and bring out the paper charts at night, a 30-40 degree course change needed to be done immediately.

Ken

Also, have a look at these two previous posts while you’re at it.

Thanks