Many of the commercially produced charts come from selections of 20 year old charts. Navionics got jobs performed in India
by a cartography company. It russiskeTransas digitized papirsøkortene in Sct. Petersburg. The same procedure with BlueChart and C -map.
When Google Earth
came, the situation and found that many shorelines were not in line with reality.
Historical chart was drawn official cartographers such as GPS
and qualified aerial photographs belonged also discovered that "short and reality" was not consistent.
Many of the commercial
charts are corrected and the corrections to the commercially produced charts works pretty but far from satisfactory acordance to Safety
The satellite images
are being misinterpreted. A boat is placed in an island is depicted as a coast projections. A boat between two islands are interpreted as two islands is an island.
Their vektor algorithm leads to islands, etc. first comes with when you zoom in very far and thus lose track of the route
. A fatal error that can cause major consequences, since it therefore becomes necessary to constantly zoom in and out.
Many rocks or boats have both been designed as islands.
They buy such. only data for a ten-meter contour and then interpolates to the coast, it provides depth
contours that do not correspond to reality. Why sailing on less than ten meters is not advisable.
At lower depth
zoom and pan, use sonar constantly and hope !!!
Giuseppe Carnevali which owns Italian Navionics trying to explain away the error:
Giuseppe Carnevali which owns Italian Navionics trying to explain away the errors with: ?? By common practice a product anses very good när har less than 1% failure rate, right beside 99% accuracy. ?? A product with 99.999% accuracy anses closer two science fiction than to reality. ?? Yet with a database (like Navionics') att contains more than a trillion objects som rocks, navigation aids, wrecks etc, 99.999% accuracy still leaves room for 10,000 errors! ?? Therefore let's face it, all charts have the errors.
How showdown to graphical errors in numbers ???
He accepts up to 10,000,000 errors in Navionics charts with 99% accuracy.
That alone provides more than 27,000 corrections from his own mistakes
every day for a year.
In addition the many new information each day to be entered in the charts and which will also contain errors coming from drawing and understanding errors.
An impossible task!
What about using the official charts, so could they even made mistakes avoided and the sailors would have a more reliable product.
Navionics has highlighted that they themselves believe that they have a better mapping than the S-57th
They also highlight that they have purchased cartographic information from the Maritime Authority of about a year back, but the agreement is not signed until 6 months later.
When incorporated a clause in the agreement can Sjöfartsverket not comment on whether Navionics cartography really buys from the Maritime Authority or not.
The above is taken from the Swedish insurance
Perhaps it would be opputunt be carried out similar studies include the Bahamas.
Brgds / Harding