The Electronic Charting "Zoom Problem"

[Dockhead]

Originally Posted by nohal

. . . .
BTW, sailing those waters discussed here is the best thing I did in my life besides the Patagonian channels and Antarctic Peninsula...

That's what everybody says about the Baltic . . .


Patagonia is also high on my list. You should write up and post about your adventures down there.

[Dockhead]

Originally Posted by transmitterdan

OpenCPN is pretty good at making routes. But when you are finished with your paper plotting you can't see your trip on Google earth with a few clicks. And you have a lot of work still left to enter the waypoints into the nav computer and the backup handheld GPS. And then if you decide to reroute you have all that to do over again. No, I think electronic way is much faster in the long run. . . .

I agree that this is a disadvantage of paper planning.

The other huge disadvantage of paper planning -- something I concretely suffered from last summer -- is that on a long cruise like mine last year you might not always have the right paper to hand. If I had bought commercial charts for my whole cruising area of last year it would have cost me several thousand dollars. So you buy where you think you're going to go, but you often end up in other places.

I have just about the entire world on my sub-kilogram laptop. I know the quality is variable, but the CM93 charts of the North Sea and Baltic are just as good as the expensive updated Navionics chips on my network, but for the odd buoy and shifting sand bank in the odd Seegat. This is a huge advantage of electronic planning.

[seandepagnier]

Originally Posted by Dockhead

I personally am not much interested in automated route planning, even if it is possible to do it well (and not like the Garmin system). I want to understand the route I'm going to be sailing and will miss the chance by not planning it myself. Others may have different points of view.

An automatic check for safety, however, according to programmable criteria, would be great.

I will keep in mind the possibility of a route-checker plugin once it's possible to query soundings. Given a route, it would check first for running aground, but also would determine closest distance to depth that could run aground.

The next step would be maybe it can check ocean currents and warn if you have significant counter-current.. can also look at swell vs current if this is available from a grib and also maybe find the maximum safe swell height along the route if the depth is shallow.

Finally it could compare known shipping routes and suggest where collisions are most likely (although this will probably end up killing someone because they assume it's safe not to look elsewhere...)

[Dockhead]

Originally Posted by RhythmDoctor

Before suggesting any software rewrites, are you guys COMPLETELY SURE that you've made full use of the "Chart Zoom/Scale Weighting" slider bar? It sure seems to me that this could address much of what you're complaining about.

And I'm really tired of hearing the "But how and why would you zoom into it if you don't know it's there in the first place?" quote. When I read that months ago I thought (and I still think) that it wreaks of self-serving finger pointing. If you want to be safe, you zoom in on every part of your route to see nearby obstacles. Most would say you should also confirm this on paper charts, though loading raster charts into OpenCPN may accomplish exactly the same thing.

And regardless of what settings you use, I've always followed the same practice for plotting routes: Zoom out to see the whole big picture and plot a crude route that goes over a bunch of obstacles, then zoom in and pan across the whole route using the most detailed chart, inserting additional route waypoints to avoid obstacles. When it's done, reverse the route (to automatically renumber), and reverse it again to automatically renumber again.

When raster charts are available, I think they are vastly superior to ENC for planning, because professional cartographers have made prudent decisions of what details are important and what can be left off. It is less subject to user error than ENC charts, which can be dangerous if the user is omitting certain elements from display.

I think people are way too eager to request complicated features to automate important safety tasks, when they should take it upon themselves to employ prudent practices to avoid obstacles. Based on what I have read, this includes the crew of Team Vestas.

I think it's an error to be tired of hearing about Team Vestas and zooming. It's a striking quote. Actually two quotes -- because the Baofang (or whatever it's called) team said almost exactly the same thing independently. This shows exactly how real sailors, even top racers, think and use their systems. Of course they should know better, but this should be a strong signal to the people who design these systems, too.

I don't want a "complicated feature" to "automate important safety tasks".

What I'd like in OpenCPN is this:

1. The ability, beyond what we have now, to quilt the more detailed level charts, independent of zoom level, into one big view if the resolution and size of our monitors permits it. Or if it's one chart and just different layers, allow us to choose the layers independently from the zoom level, overriding the automatic change of layers with zoom level. Surely that won't be too hard? With that, we can use big high res monitors to get the "big view" so many of us crave, similar to what we get from paper.

2. The more complicated feature would be this: in lower zoom levels (zoomed out) where the details disappear, generate some proxy for missing details according to some configurable safety criteria. Maybe the goal should be to show safe water, rather than hazards -- yeah, probably that's easier and more logical. So that safe water ("safe" according to user configurable criteria) is shown in the highest resolution the monitor can show, at the lowest zoom levels (zoomed out). That way, if I were Team Vestas, for example, I could see that whole sector of the Indian Ocean, and it would all be blue, for example, but it would have brown or gray blotches in areas where there is not safe water. That would tell me "how do I know where to zoom in?"

This would do too things: (a) remind me to pan through the whole route again; (b) allow me to see at a glance the "crude route" for planning purposes at any zoom level, for waters too complicated to just lay out a rhumb line.

[colemj]

Originally Posted by Dockhead

I think it's an error to be tired of hearing about Team Vestas and zooming. It's a striking quote. Actually two quotes -- because the Baofang (or whatever it's called) team said almost exactly the same thing independently. This shows exactly how real sailors, even top racers, think and use their systems. Of course they should know better, but this should be a strong signal to the people who design these systems, too.

Take another look at the two chart pictures posted in post #44 and ask yourself if you really believe that quote.

Yes, the actual above water portion of the shoal does not show up when zoomed out on the vector chart, but tell me if you would have glanced at that with the intent to pass right over it and NOT zoomed in a bit.

It was not invisible or unknowable.

Mark

[valhalla360]

Originally Posted by Dockhead

Nevertheless, Team Vestas managed to hit an island. For long ocean passages, of course, the planning is usually straightforward -- a great circle course which is fairly obvious, and you just need to check it for obstacles. Panning through it on a plotter is ok for that, and if Team Vestas had done that, they would not have lost their boat.

Sailing "narrow inland routes" and staying out of trouble can also be done perfectly well without paper. Just keep your eye on the plotter and keep the plotter at a sufficient zoom level and you're fine.

The problem arises when you need to plan a route -- find a way -- through complex water. That's a completely different problem.

No unbiased evidence says paper charts would have helped them. You are presuming it would but there is no evidence that it would have. Also, if they were monitoring thier passage on a regular basis, it wouldn't have been a problem. They failed to keep a lookout (in this sense watching the chart plotter periodically to know what was in the vicinity). As you quoted in a later post, they weren't checking the chart on a regular basis.

Simple logic suggests you zoom in close enough to see what is in the vicinity periodically and the issue would have been solved without paper charts. At least that is what we do. Their excuse that they shouldn't be expected to check is a mistake on thier end not a fault of planning with electronic charts.

I also hesitate to presume racer = seamanship. Racers are often willing to take risks, push the limits and cut corners your average cruiser wouldn't in the name of getting there a little quicker.

What complex waters are you speaking off? If it's a complex situation, you should be zoomed in and checking your position vs the charts on a regular basis (as in in minutes not hours between checking) negating any issues with long range planning.

The only place I can potentially see an advantage is if there are a lot of dead end routes and you have to pan back and forth to find a way thru but that is a convienence issue not a safety issue. Reality is they frequently show a common route when it is that complex.

So far you've not convinced me nor a few others that it is "dangerous" to plan with electronic charts...so your opening statement is pattently false.

[Dockhead]

Originally Posted by colemj

Take another look at the two chart pictures posted in post #44 and ask yourself if you really believe that quote.

Yes, the actual above water portion of the shoal does not show up when zoomed out on the vector chart, but tell me if you would have glanced at that with the intent to pass right over it and NOT zoomed in a bit.

It was not invisible or unknowable.

Mark

Yes, there is a blue blotch for that particular hazard even at lowest zoom settings. Yes, they should have zoomed in and checked it out -- they screwed up big time, and there is no question about it.

But this is still an important indication of the way people actually work with chart plotters. And many hazards disappear completely at low zoom settings, even moderately zoomed out, leaving what looks like blank safe water.

Even if you are using OpenCPN, and even if you are using the "Chart Zoom/Scale Weighting" slider.

[sailorF54]

Originally Posted by boat_alexandra

The thread is 50 pages... any idea which page? I want to download charts for indonesia and the indian ocean if possible. Thanks.

Those charts are no longer available, as NGA realized after a while that as many were based on non US charts, it did not have the right to make them available for free, not holding the proper copyright.

[NahanniV]

Originally Posted by sailorF54

Those charts are no longer available, as NGA realized after a while that as many were based on non US charts, it did not have the right to make them available for free, not holding the proper copyright.

Where could we find your .zip file ?

Cheers,
JM.

[sailorF54]

Originally Posted by NahanniV

Where could we find your .zip file ?

Cheers,
JM.

http://dl.free.fr/puUENSu2n

[colemj]

Originally Posted by Dockhead

Yes, there is a blue blotch for that particular hazard even at lowest zoom settings. Yes, they should have zoomed in and checked it out -- they screwed up big time, and there is no question about it.

But this is still an important indication of the way people actually work with chart plotters. And many hazards disappear completely at low zoom settings, even moderately zoomed out, leaving what looks like blank safe water.

Even if you are using OpenCPN, and even if you are using the "Chart Zoom/Scale Weighting" slider.

I'm sorry, but you are sticking to an argument that has deflated.

Anyone who plotted a route through that area of 3,000' depth right over a big blue warning blotch without zooming in to check the area out a bit - would certainly have problems navigating with a paper chart also.

Which brings me to a point I keep raising and everyone keeps ignoring because it does not fit their narrative - Team Vestas WAS navigating using paper charts. They were certainly using them with as much skill, and to as much effect, as they did their electronic ones - but they were "using" them.

There is even a freaking PICTURE on their website of the navigator holding the paper chart!

Again, this point is widely ignored by people because it does not fit the narrative supporting their viewpoint.

As a lawyer, you must understand better than others that if the glove don't fit, you must acquit.

Can we all please accept the Vestas thing for what it is and stop appropriating it for what it isn't?

Now, back to the point - if people do not understand how to use tools, you cannot blame the tools. In the past, lots of people came to grief misusing, or not understanding, how to use a sextant. Or even making simple math errors using the reduction tables. Should people back then have been railing on sextants, and their use for navigation?

Mark

[NahanniV]

Originally Posted by sailorF54

Free - Envoyez vos documents

Thanks !

Are any of the small scale charts still available anywhere ?

Cheers,
JM.

[Dockhead]

Originally Posted by colemj

I'm sorry, but you are sticking to an argument that has deflated.

Anyone who plotted a route through that area of 3,000' depth right over a big blue warning blotch without zooming in to check the area out a bit - would certainly have problems navigating with a paper chart also.

Which brings me to a point I keep raising and everyone keeps ignoring because it does not fit their narrative - Team Vestas WAS navigating using paper charts. They were certainly using them with as much skill, and to as much effect, as they did their electronic ones - but they were "using" them.

There is even a freaking PICTURE on their website of the navigator holding the paper chart!

Again, this point is widely ignored by people because it does not fit the narrative supporting their viewpoint.

As a lawyer, you must understand better than others that if the glove don't fit, you must acquit.

Can we all please accept the Vestas thing for what it is and stop appropriating it for what it isn't?

Now, back to the point - if people do not understand how to use tools, you cannot blame the tools. In the past, lots of people came to grief misusing, or not understanding, how to use a sextant. Or even making simple math errors using the reduction tables. Should people back then have been railing on sextants, and their use for navigation?

Mark

No one ever blamed the Vestas accident on the charts, electronic or otherwise. The very phrase of the team itself was "user error" -- they admitted it.

They may have had paper charts, but according to their accounts they were relying on their electronic navigation at the time of the accident. If they had either checked the paper or panned through their route on their plotters -- an elementary safety procedure -- they would not have had the accident.

OK, now that we've got that out of the way -- the Vestas accident, especially the comments made by the teams, is still extremely relevant to this question.

It does not follow logically that because they could have avoided the accident themselves, and even should have avoided the accident themselves, that the tools can't or shouldn't be improved, taking into account the realistic, practical way that people work and think.

The specific point here is that when people see a blank when they look at zoomed out electronic charts, they tend to assume -- probably unconsciously -- that this is empty ocean -- safe water. Even top racers. Even when there is a blue blotch as in the Vestas case (and usually there isn't any blotch). So you can say -- everyone is an idiot who makes this assumption, and to hell with them. Or you can say -- let's adapt the tools to work better according to the way people naturally and instinctively visualize displayed data. You can make your own choice; mine is the latter.

No one is "railing on" the tools we have. We're just trying to improve them. They are good, but they could be better still. That's how progress happens.

[colemj]

Originally Posted by Dockhead

No one ever blamed the Vestas accident on the charts, electronic or otherwise.

You obviously have not been reading the threads, or even some of your own statements.

I am still not seeing the broad problems you are having in the tools you are using. You asked a couple of people to perform an exercise you have problems with and they came right back and said it was easy.

A few others of us have told you that we don't have the same problems as you planning and navigating with electronic charts and devices.

Your response to this so far has been to attempt to root out someplace on earth where it can be shown that a paper raster chart would be a better option for planning. Maybe those places exist and this is the best option there, but it is hardly representative of the vast majority of planning people do.

Vector charts and the devices that use them will probably never be as broadly similar to a large paper raster chart that you desire.

But that does not mean that the path forward is to attempt to achieve this. You may find that a 48" screen projecting raster charts is a good solution, but many of us are shaking our heads.

IMO, attempts to automate electronic route planning because it is "so difficult" would lead to far more problems than people who do not spend the time to understand their tools and how to use them.

You started this thread with a very faulty premise that you continue to stick to - and this is the basis of the problem you are having.

Mark

[Dockhead]

Originally Posted by colemj

You obviously have not been reading the threads, or even some of your own statements.

I am still not seeing the broad problems you are having in the tools you are using. You asked a couple of people to perform an exercise you have problems with and they came right back and said it was easy.

A few others of us have told you that we don't have the same problems as you planning and navigating with electronic charts and devices.

Your response to this so far has been to attempt to root out someplace on earth where it can be shown that a paper raster chart would be a better option for planning. Maybe those places exist and this is the best option there, but it is hardly representative of the vast majority of planning people do.

Vector charts and the devices that use them will probably never be as broadly similar to a large paper raster chart that you desire.

But that does not mean that the path forward is to attempt to achieve this. You may find that a 48" screen projecting raster charts is a good solution, but many of us are shaking our heads.

IMO, attempts to automate electronic route planning because it is "so difficult" would lead to far more problems than people who do not spend the time to understand their tools and how to use them.

You started this thread with a very faulty premise that you continue to stick to - and this is the basis of the problem you are having.

Mark

Man, you love to argue. You should have been a lawyer

The premise, or rather premises of this thread are manifestly not false (actually there are two premises). It is a fact well known to anyone who navigates in complex water that it is difficult to plan passages with the electronic tools we have available to us. Practically impossible on a regular plotter (as several on here have said). A skillful operator using OpenCPN can do a lot better, as two on here have demonstrated. And some on here have argued that they are skillful enough with this particular tool not to need paper at all -- fair enough. But "easy"? Spend a season in the Baltic without paper and come let us know how your normal work flow works out for you -- I guarantee it will knock down your confidence in how "easy" this is by three or more notches. The great majority of sailors here simply will not use electronic means of any kind for planning passages -- cf Carsten from Denmark. Because your waters are different, does not mean your experience is universal. Because it's not a problem for you, does not mean that it is not or shouldn't be a problem for anyone. The problem I am writing about is universally known to sailors here -- ask any Baltic sailor.

That's one of my premises -- that our electronic tools could be better for planning routes in complex water.


The other premise of this thread is that it could be easier to visualize hazards in zoomed out charts. So you say this premise is also false? There's no problem, right? You have to be an idiot to see a blank screen and assume that there is safe water there, therefore the tools are already perfect and require no improvement - right?

You're entitled to your own opinion about it, but I disagree.