Another foundering how do chart plotters get it wrong

[minaret]

Originally Posted by FamilyVan

Dude, over reliance on a single piece of equipment has been my only argument since the beginning.
You have disagreed with every post I've made. So yes, you have been arguing against my only argument.
Now please, leave me alone. I'm not interested in what you have to say.

Sent from my SGH-I547C using Cruisers Sailing Forum mobile app

Get used to it if you're going to be on the forum much. It's usually the same people. Judicious use of the ignore button will save you much grief. Wrestle with pigs and you just end up smelling like sh*t. Or, as Mark Twain put it, never argue with an idiot, it may not be clear to an onlooker who the idiot is, or something similar. Professionals who actually know their trade receive much grief from armchair wannabes here. And you are a pro navigator, that will really ruffle some feathers. But stick to it, and remember the majority of those who read what you write are not posting. You have an opportunity to spread knowledge and do some good if you stick around. You just have to learn who to ignore.

[Wotname]

Originally Posted by colemj

................

A chart plotter does not MAKE people do things. That is confusing correlation with causation. Many posters here want to perceive a relationship between the two because it fits their worldview and biases.
..................

Mark

I'm not sure anyone has suggested this; for my part, I suggest chartplotters ALLOW people to do things that aren't wise (in a navigational sense) and that such unwise things would be more difficult when using traditional methods. But don't take the chartplotter away, learn to use it wisely.

Originally Posted by colemj

Originally Posted by Wotname
The function of the plotter remains the same but the effect it has on the operator is different. I'm not sure some of the posters here understand the difference

.................................................. .................................................. ................


Can you provide any evidence for this, or at minimum a good argument for it?

And explain how it is different from someone getting into trouble without a chartplotter? I have provided 9 examples of people losing their boats attempting to navigate a reef with paper charts that did not contain the more accurate data of the corresponding electronic charts, but I have not said that paper charts have any effect on people - even in the face of posters actually saying that the only faith they have is in paper charts.

If the effect chartplotters have on their operators is so dangerous, are you suggesting they should be banned or licensed?

Mark

Please re-read post 189 and get back to me if you can't follow the logic presented there or find a fundamental flaw in it. I don't mind if you want to hold a differing view

I don't want anything banned or licensed; I would just like people to be educated about the limitations of chartplotters. Evidence would suggest not everyone is aware that there are some drawbacks; however let me reiterate, I do believe the benefits of them are many.

[transmitterdan]

Originally Posted by FamilyVan

So TransmitterDan. I'll ask you the same question I posed to Mark. "Another foundering how do Chartplotters get it wrong?". Or are you satisfied with just making false accusations?

Sent from my SGH-I547C using Cruisers Sailing Forum mobile app

I have no idea if this particular foundering was due to a chart plotter "getting it wrong". If you know it to be so it would be good to lay out the details. But in the vast majority of real world experiences the chart plotter will get it right. Are there cases where specific machines with specific charts have been wrong? Yes. Was it operator error? Sometimes. Has this resulted in foundering?

I have yet to hear of a specific case where a "wrong" chart plotter was the proximate cause of a grounding. Vestas Wind has been raised as a "strawman" but that wasn't the cause as far as I have heard. They just screwed up plain and simple. The reef was in their chart plotter. If anyone has information that the chart plotter on board VW was "wrong" I have yet to hear of it and would like to know more. All the other boats went safely around that reef. That wasn't dumb luck was it? I would like to think the others managed to avoid the reef by checking their track on their plotter.

If the original question had been "How do people wrongly use chart plotters and end up on the rocks?" that would be a great discussion I imagine. But the reality is that the technology is way more reliable than paper, pencils and dividers. And if people refuse to use this tool because of some unfounded belief that it is often wrong then that's a disservice to people entering this field.

We need to face up to the fact that printed charts will eventually be unaffordable due to lack of sales volume. Carriage is no longer mandated by regulators so used charts are rarer than ever. Eventually no one will produce them. Will that happen in my cruising lifetime? Probably not but the undeniable trend is there. Cruisers would be well served by experienced navigators espousing how to survive in an electronic world.

For the record I am not advocating using GPS alone. But it is absolutely the most accurate and reliable way for recreational sailors to find their position relative to the rest of the world. There are other methods such as radar in close quarters but that doesn't work out in the open ocean. AIS tells you where the other guy is but without a chart plotter telling you where you are that information is nearly useless. How in heavens name is someone supposed to plot 20-30 moving AIS targets on a paper chart? It's not feasible.

[FamilyVan]

Originally Posted by transmitterdan

I have no idea if this particular foundering was due to a chart plotter "getting it wrong". If you know it to be so it would be good to lay out the details. But in the vast majority of real world experiences the chart plotter will get it right. Are there cases where specific machines with specific charts have been wrong? Yes. Was it operator error? Sometimes. Has this resulted in foundering?

I have yet to hear of a specific case where a "wrong" chart plotter was the proximate cause of a grounding. Vestas Wind has been raised as a "strawman" but that wasn't the cause as far as I have heard. They just screwed up plain and simple. The reef was in their chart plotter. If anyone has information that the chart plotter on board VW was "wrong" I have yet to hear of it and would like to know more. All the other boats went safely around that reef. That wasn't dumb luck was it? I would like to think the others managed to avoid the reef by checking their track on their plotter.

If the original question had been "How do people wrongly use chart plotters and end up on the rocks?" that would be a great discussion I imagine. But the reality is that the technology is way more reliable than paper, pencils and dividers. And if people refuse to use this tool because of some unfounded belief that it is often wrong then that's a disservice to people entering this field.

We need to face up to the fact that printed charts will eventually be unaffordable due to lack of sales volume. Carriage is no longer mandated by regulators so used charts are rarer than ever. Eventually no one will produce them. Will that happen in my cruising lifetime? Probably not but the undeniable trend is there. Cruisers would be well served by experienced navigators espousing how to survive in an electronic world.

For the record I am not advocating using GPS alone. But it is absolutely the most accurate and reliable way for recreational sailors to find their position relative to the rest of the world. There are other methods such as radar in close quarters but that doesn't work out in the open ocean. AIS tells you where the other guy is but without a chart plotter telling you where you are that information is nearly useless. How in heavens name is someone supposed to plot 20-30 moving AIS targets on a paper chart? It's not feasible.

Sorry Dan, not rising to the bait. I don't have the time or the interest in rewriting the posts I've written.
Don't count on me to educate you- educate yourself.

Sent from my SGH-I547C using Cruisers Sailing Forum mobile app

[downunder]

Originally Posted by FamilyVan

You're probably right about many people not being able to plot a position. I have a friend with a 38' sailboat, full time live aboard for years, and is still working on his fundamental navigation skills, but he is working on them.

The thought of somebody crossing seas and oceans without having taken some navigation courses gives me the willies- clearly it happens though.

Having said that I believe a balanced approach could still be used. That's the beautiful thing about the ColRegs Rule 5. The common interpretation is that you navigate with all means at your disposal. Therefore if you can't tell the title block from a sounding on your chart- or you don't have one on board, it really isn't at your disposal.

Very few of these $1/2 million dollar yachts sailing around with untrained navigators are equipped with ONLY a Chartplotter. I would hazard to guess the lowly depth sounder and magnetic compass are far more common than Chartplotters. For flash yachts out there RADARs are almost always equipped. Its part of the status symbol.

So even if their balanced approach doesn't include the use of paper charts, they can still use their sounder, eyes, ears, monitor traffic on their VHF, play with their RADAR and see if they can get some useful information from that. I guess look at their position on their cell, but I would never encourage somebody to navigate with cheap disposable items like cells and tablets. Google images of their destination before hand etc.

I really can't see why, even if you lack basic navigation skill you can't take a prudent and procedural approach to navigation.

I would also encourage people to stay well within the reach of their local Search and Rescue station until they have accumulated the skills appropriate to their endeavour.

My argument isn't for or against paper or electronic charts. I might even buy myself an electronic chart one day. My argument is for the process you use. The checks and balances that you should have in place for your own safety.

Certainly if someone lacks basic navigation skills, it's irresponsible of them to go on the internet and start telling an unknown audience that you don't need to be prudent when navigating a 20 000 lb status symbol across oceans.

Sent from my SGH-I547C using Cruisers Sailing Forum mobile app

Whilst Radar might be see by some as a status symbol those of us that were navigating with radar before chartplotters were readily available still see them as an extremely valuable tool and a very important check for your position.

[lordgeoff]

Originally Posted by transmitterdan

I have no idea if this particular foundering was due to a chart plotter "getting it wrong". If you know it to be so it would be good to lay out the details. But in the vast majority of real world experiences the chart plotter will get it right. Are there cases where specific machines with specific charts have been wrong? Yes. Was it operator error? Sometimes. Has this resulted in foundering?

I have yet to hear of a specific case where a "wrong" chart plotter was the proximate cause of a grounding. Vestas Wind has been raised as a "strawman" but that wasn't the cause as far as I have heard. They just screwed up plain and simple. The reef was in their chart plotter. If anyone has information that the chart plotter on board VW was "wrong" I have yet to hear of it and would like to know more. All the other boats went safely around that reef. That wasn't dumb luck was it? I would like to think the others managed to avoid the reef by checking their track on their plotter.

If the original question had been "How do people wrongly use chart plotters and end up on the rocks?" that would be a great discussion I imagine. But the reality is that the technology is way more reliable than paper, pencils and dividers. And if people refuse to use this tool because of some unfounded belief that it is often wrong then that's a disservice to people entering this field.

We need to face up to the fact that printed charts will eventually be unaffordable due to lack of sales volume. Carriage is no longer mandated by regulators so used charts are rarer than ever. Eventually no one will produce them. Will that happen in my cruising lifetime? Probably not but the undeniable trend is there. Cruisers would be well served by experienced navigators espousing how to survive in an electronic world.

For the record I am not advocating using GPS alone. But it is absolutely the most accurate and reliable way for recreational sailors to find their position relative to the rest of the world. There are other methods such as radar in close quarters but that doesn't work out in the open ocean. AIS tells you where the other guy is but without a chart plotter telling you where you are that information is nearly useless. How in heavens name is someone supposed to plot 20-30 moving AIS targets on a paper chart? It's not feasible.

"But GPS is absolutely the most accurate and reliable way for recreational sailors to find their position relative to the rest of the world." You could amend this sentence as follows?
"But GPS is absolutely the most accurate and reliable AND FASTEST way for ALL sailors to find their position relative to the rest of the world.

[Rustic Charm]

I recently had my mooring tackle lifted and inspected. When they put it back they put it back in the wrong place, which would have it hitting another yacht. My club had it then lifted again and out back. Apparently both club and tackle company both used gps, both said they put it down in the same place.

I'm also conscious that two years ago a well known contestant in the Tasmanian three peaks race ran aground on the way to Flinders Island near Badger Island. I'm informed they were following their chart plotter without reference to the charts and as a result grounded.

What makes marine chart plotters any more accurate than mobile/car ones?

I was using one in my work car the other day and if I had followed it without question I would have ended up in the River.

[carstenb]

Guys - I tried to get this thread back on track, You're getting very close to violating our "be nice" rule and I really don't want to have to spend a lot time cleaning this thread up. Please refrain from the personal comments about other posters. The subject is interesting and can be discussed without disparaging others point of view.

Please "be nice"


carsten

[hoppy]

I just bought a 2nd MFD unit in my boat. Does that make me twice as likely to run aground now?

There's nothing wrong with chart plotters, there's nothing more wrong with the charts on them compared with paper and with the exception of poor satellite reception areas you are not going to be as accurate finding your position manually.

How people use the GPS or paper maps is why boats run aground. If you set a course to be half a mile off some rocks in 5 miles sailing and don't occasionally check to see that you are maintaining your course, then **** happens.

[Wotname]

Originally Posted by hoppy

I just bought a 2nd MFD unit in my boat. Does that make me twice as likely to run aground now?

There's nothing wrong with chart plotters, there's nothing more wrong with the charts on them compared with paper and with the exception of poor satellite reception areas you are not going to be as accurate finding your position manually.

How people use the GPS or paper maps is why boats run aground. If you set a course to be half a mile off some rocks in 5 miles sailing and don't occasionally check to see that you are maintaining your course, then **** happens.

And now you will be able to check your course twice as often

[Capex]

Re the OP: There are a number of reasons that people go aground as has been pointed out already here. However, in my experience over the past 25 years of navigating around SE Asia and talking to cruising yachtsmen, the incidence of the chart plotter giving a paper chart position "5 miles inland" occurs quite frequently. When more closely questioned on their methods of navigation, it appears that many fail to read the Chart Datum and adjust their chart plotters accordingly. In this particular area there are variations from Thai Datum (actually Indian Datum) to WGS 84 (the standard setting) to WGS 72, to Indonesian Datum. These variations can amount to serious differences in actual distances off hazards.
Then there are the sailors who mark a hazard as their waypoint and wonder why the hell they have run aground!! I can think of one French sailor whose navigation was accurate and doing exactly that and landing on the rocks on Racha island while he was sleeping below.
Many people ignore the warning when the instrument is loading that says "This is an aid to navigation only" Press Accept.

[FamilyVan]

Originally Posted by downunder

Whilst Radar might be see by some as a status symbol those of us that were navigating with radar before chartplotters were readily available still see them as an extremely valuable tool and a very important check for your position.

I totally agree with you. I think RADAR is a fantastic tool and has gotten me out of many jams. Real time information, a real image of surrounding floating and fixed objects. Excellent collision avoidance capabilities. Proven reliability. The ability to function independently of other equipment. The ability to parallel index, the accuracy of electronic bearing lines. The accuracy of range and bearing fixes in near shore situations.

Please don't take this one wrong- we're on the same page on RADAR.

Please note the context of the discussion when I made this post.

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[boatman61]

To me the whole Thread as been a Strawman Thread..
No one KNOWS why they grounded... just the usual CF speculation.. not that that's a bad thing but.. I know how wrong it can be.. and what it can lead to...
The CP will be as wrong as paper on occasion.. same source so it stands to reason.. also sometimes there's glitches in the system.. the Kanakale affair was not my only experience of GPS error over the years.. off the entrance to Soller, Mallorca it showed me down by Dragonera once.. in the S Pacific it was 1/2 mile out entering Samoa.. when I left 2 weeks later showed the right picture..
Go figure...
Hoppy... for the 'Greens'... state the course you chose.. COG or COW... in the Med its not so serious... but in the N France and other fast tidal regions the difference is fatal.. if you follow the wrong one..
Play on Chaps...

[transmitterdan]

Mere mortals have a difficult time computing COG without a chart plotter.

It would be good if we state how many years ago it was when the GPS showed us in different places on different days. Since about 1999 the civilian system has been accurate to several meters. Before that it was intentionally fiddled with by the US gov. And people should know how to read the position error estimate. Most plotters can show it as a ring of uncertainty but a lot of people turn it off. And I think this is a shortcoming of some home built MFDs using tablets or laptops. They often can't show the position error estimate. That can lead to over confidence and trouble. This is also a concern with mobile phones. When the signal is weak or lost they may estimate position from cell towers but the uncertainty can be more than a kM.

I don't have experience with the Russian system. Would like to know how often they fiddle with the accuracy of that system.

I'm not saying GPS should be the only means of determining position. But it is almost always the most accurate. And when it isn't it will usually tell you if you are willing to see it.

[denverd0n]

Originally Posted by transmitterdan

Mere mortals have a difficult time computing COG without a chart plotter.

Wow. I guess I will take that as a compliment, as I find it pretty easy to determine my COG without a chart plotter. Thank you.

But really. Eighteen pages of this? The original question was answered on page one, and nothing new has been added since about page three. It's beginning to look a bit like two kids on the play ground, endlessly going back and forth with "did too," "did not," "did too," "did not."

Still, that's the entertainment value of the internet, isn't it?