Many dangerous errors in new Navionics cartography

Little Grebe said:
Navionics gave a presentation at my club at the beginning of the season and they stated that the "base" charts were only updated from official sources and wouldn't make changes based on user reports.

The Sonar Charts seem to be a big thing for them to the extend they were loaning out combined echo sounders and GPS units which could be fitted to smaller craft without integrated electronics.
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Well I think they were telling you porkies, because the data for both the base chart and sonar chart for Saint Vaast was changed 6 weeks ago to show the non-existent channels (which have now been removed again).
 
AntarcticPilot said:
If someone suffers damage or loss from these charts, I doubt very much that a "Not for Navigation" notice would suffice to keep Navionics from being liable to pay damages.
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I, in turn, would hope that the courts would throw out any such claim unless there was evidence of gross or maliciously wilful negligence. Responsibility for navigation remains with the master - he may have excuses but the accuracy of third party information is always doubtful, even Admiralty charts.
 
As someone pointed out Sir Tom has returned to the theme of Vector vs Raster charts on page 26 of Sept YM. He showed two examples of charts of Fishcombe Cove near Brixham.

The Raster chart was so poor it bore little relation to the bay in question. A useless piece of kit by any measure. He did not name it. However, it seems to me, that it was useless not because it was a raster chart but because it was a bad piece of work.

Wish I could put the examples on here but my scanner has bust.
 
All_at_Sea said:
These are the sailing club owned buoys surely? They allow visitors to stop there.
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Nope. The Pilot mentions both - the Eastney Cruising Association buoys on the west side (still there as far as I know) and a set of visitors' moorings controlled by the harbourmaster on the east side. The latter have not existed for as long as I've owned a boat.

Pete
 
Back to base charts changing. .. about a year ago there was a thread that discussed the new drying area in Osborne Bay and the sandbank just off Southsea just to the west of Langstone Harbour entrance.

I've not updated the base map on my plotter for a few months but have just noticed on their Web app that not only has the sand spit reduced again, but there is now a 4m below datum hole in the middle of it. .that deep bit wasn't there a couple of months ago !
 
Martin_J said:
Back to base charts changing. .. about a year ago there was a thread that discussed the new drying area in Osborne Bay and the sandbank just off Southsea just to the west of Langstone Harbour entrance.

I've not updated the base map on my plotter for a few months but have just noticed on their Web app that not only has the sand spit reduced again, but there is now a 4m below datum hole in the middle of it. .that deep bit wasn't there a couple of months ago !
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This thread:

http://www.ybw.com/forums/showthread.php?378920-New-Solent-banks-drying-above-CD-according-to-iPad-Navionics

Turns out that those changes (drying heights) that appeared on Navionics charts did not exist and were subsequently removed. (I can't comment on whether the depths showing there now have changed recently).


Edit: also this one: http://www.ybw.com/forums/showthread.php?380288-Portsmouth-Inner-Swashway
 
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Martin_J said:
Back to base charts changing. .. about a year ago there was a thread that discussed the new drying area in Osborne Bay and the sandbank just off Southsea just to the west of Langstone Harbour entrance.

I've not updated the base map on my plotter for a few months but have just noticed on their Web app that not only has the sand spit reduced again, but there is now a 4m below datum hole in the middle of it. .that deep bit wasn't there a couple of months ago !
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Is your last sentence a reference to the area around Osborne Bay or the Winner (off Langstone)?

I've just compared what is currently showing on the Navionics Webapp and the Admiralty charts on VisitMyHarbour and there is indeed a difference between the two in the vicinity of Peel Wreck Buoy (I can't find the exact lat and long, but about 50 deg 44.9 N, 01 deg 13.4W). To the north, west and south of that buoy, the Admiralty chart is showing depth of between 2 and 4 metres below datum. The Webapp is showing mostly below 4m, with a few patches to the south of the buoy below 5m.

The downside of the VisitMyHarbour is that you can't be sure how up to date the charts displayed are as they don't always include the part of the chart with the "last printed" date on it.

Edit: I think I have found your 4m "hole" on the West Winner - showing on the Navionics webapp, but absent from the charts on VisitMyHarbour (which gives depths in that area generally between datum and datum less 2m and with a patch above datum to the west which is completely missing from Navionics). Again, no idea how recent the Admiralty chart on VisitMyHarbour is.
 
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UPDATE: Since I reported these errors to Ellie Cox of Navionics Data Sourcing department at the Southampton Boat Show, the buoys and drying patch have disappeared from the charts. Today I noticed that they have also deleted the spurious "rocks"from Stangate and connected creeks, though they remain in the nearby Swale. Also they still show a non-existent drying patch at the south end of Queenborough All Tide Landing. Still we are not being told where they get their data from!
 
I totally agree that Navionics cartography leaves a lot to be desired but a minor quibble - I don't see these as dangerous errors! It would be dangerous if they left out mooring buoys, drying patches, rocks etc., leaving ones in that don't exist is merely inconvenient

Although the inaccuracies do make one wonder what does get left out!
 
tony_lavelle said:
UPDATE: Since I reported these errors to Ellie Cox of Navionics Data Sourcing department at the Southampton Boat Show, the buoys and drying patch have disappeared from the charts. Today I noticed that they have also deleted the spurious "rocks"from Stangate and connected creeks, though they remain in the nearby Swale. Also they still show a non-existent drying patch at the south end of Queenborough All Tide Landing. Still we are not being told where they get their data from!
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Erbas said:
I totally agree that Navionics cartography leaves a lot to be desired but a minor quibble - I don't see these as dangerous errors! It would be dangerous if they left out mooring buoys, drying patches, rocks etc., leaving ones in that don't exist is merely inconvenient

Although the inaccuracies do make one wonder what does get left out!
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It's dangerous because if you find errors of one type, it may well mean there are errors of the other type!

And while I'm glad Navionics have responded so rapidly, the very speed of their response has me wondering if they really checked the report. Not that I doubt the accuracy of the report - but Navionics should be in the business of cross-checking things.
 
tony_lavelle said:
UPDATE: Since I reported these errors to Ellie Cox of Navionics Data Sourcing department at the Southampton Boat Show, the buoys and drying patch have disappeared from the charts. Today I noticed that they have also deleted the spurious "rocks"from Stangate and connected creeks, though they remain in the nearby Swale. Also they still show a non-existent drying patch at the south end of Queenborough All Tide Landing. Still we are not being told where they get their data from!
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I had a whinge at someone on the Navionics stand at the boat show.

They were very polite and took my comments in a good manner. They pointed out how I could most easily report errors in their data. I explained that I would not be doing so, as I never intend to buy another Navionics product until I am confident that no spurious user supplied data can ever find its way onto their electronics charts.
 
Erbas said:
I totally agree that Navionics cartography leaves a lot to be desired but a minor quibble - I don't see these as dangerous errors! It would be dangerous if they left out mooring buoys, drying patches, rocks etc., leaving ones in that don't exist is merely inconvenient

Although the inaccuracies do make one wonder what does get left out!
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The channels at Saint Vaast that made it onto the Navionics charts at the start of August were most definitely dangerous. Saying there are ways into the harbour that are a couple of metres below datum when in fact they are a couple of metres above could lead to disaster. You also wouldn't have been very popular with the locals if you took out their oyster beds with your keel. :disgust:
 
Angele said:
The channels at Saint Vaast that made it onto the Navionics charts at the start of August were most definitely dangerous. Saying there are ways into the harbour that are a couple of metres below datum when in fact they are a couple of metres above could lead to disaster. You also wouldn't have been very popular with the locals if you took out their oyster beds with your keel. :disgust:
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Ok, that one is a dangerous error!
 
Angele said:
They pointed out how I could most easily report errors in their data. I explained that I would not be doing so, as I never intend to buy another Navionics product until I am confident that no spurious user supplied data can ever find its way onto their electronics charts.
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+1

it's not only the addition of outside data without any corrections, verification nor confidence intervals, which in itself is beyond any sensible approach(let alone Sonar charts where they eventually admitted they should only be used for fishing), imho there is worse: they also "built" their own depth contours by -as two different people at two different boat shows explained- "rebuilding a mathematic sea bottom surface with the official contours, then slicing it horizontally ad libitum obtaining as many bathymetric contours as needed", which is total nonsense. I have been involved in similar data treatment (in different fields) and can say the persons who explained their process really had some understanding of what was involved.

for a festival of errors, just have a look at this thread (among others), no need to read French just look at the attached pictures

http://www.hisse-et-oh.com/forums/n...ionics-faire-confiance-aux-nouvelles-versions


also, as you say Angele, I do not understand their policy: "please report errors so we can correct our charts" ?
First they should not provide charts with very doubtful interpolations added by themselves
Second, how can they aim to provide a commercial product asking the massive help from their own customers
Third, how do they decide which correction is acceptable and which one is not? "We check against official data", ok then why they do not use official data ONLY since the beginning?

r
 
I had thought about buying the Navionics cartography app for many months, but your findings have really put me off, I have an Horizon cp300i, but to support it, I'm going with the visit my harbour offering,with Rasta charts.
 
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