New podcast episode: FreeNauticalChart - How free is open data really?
Antonia von Lamezan
· 29.05.2026
The idea: Freely accessible nautical charts
It all started with a practical problem: Adam Lucke was looking for current depth data and the position of buoys for a cruise in the Dutch mudflats. He found freely available, weekly updated chart data on Dutch websites. Easy to download and available to everyone.
The Dutch make this data available online as an electronic map, freely accessible",
Adam Lucke explains in the podcast.
He then asked himself: is there anything like this in Germany? He found the answer in the GeoSeaPortal of the Federal Maritime and Hydrographic Agency (BSH). There, nautical chart data was available as open data, licensed in accordance with the Geodata Utilisation Ordinance, which is intended to enable precisely this: Citizens are allowed to use government data for useful applications.
From this freely accessible BSH data, Adam Lucke finally developed FreeNauticalChart.net - a free online nautical chart, supplemented by additional data sets such as a tidal calendar and a tidal current atlas.
Then the article appeared - and the data was suddenly gone
After YACHT had reported on the projectan unexpected development occurred: Data has been removed from the BSH server. "BSH itself never spoke to me," says Adam. "I can only see that certain data is suddenly no longer there on the server."
The official reason given by the BSH was that the data was not reliable enough for navigation. They did not fulfil the quality requirements of official nautical charts.
The central question: Is it the same data?
Lucke has made a random comparison: The open data charts appear to be identical to the official nautical charts. "They are effectively the same data," he says. The difference is probably purely formal: the BSH provides a guarantee for official charts, but not for open data. It seems even more absurd with commercial nautical chart apps. They also use BSH data and are often supplied as an additional service to the purchased paper chart. However, they exclude any liability in their terms and conditions. "It says in there: We guarantee neither up-to-dateness nor correctness," explains Lucke. "So why go to all this trouble with the purchased BSH data?"
Adam Lucke suspects that the economic interests of nautical chart manufacturers are behind the removal of public data sets. His clear stance: a federal authority should be committed to the common good. He is therefore calling for transparency in this matter.
Listen now
The full story, technical background and the question of how to handle public data correctly can be found in episode 74 of the YACHT podcast with Timm Kruse.
The BSH's statement will follow on 5 June in a separate podcast episode.
Here you can listen to the YACHT sailing podcast with Adam Lucke
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Antonia von Lamezan
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