About the BSBD data

Source data

Each Baltic Sea country’s territorial waters and Exclusive Economic Zone (EEZ) is based on data sets provided by the respective national hydrographic authority. Some of these data sets are publicly available, and some are only provided to BSHC for the compilation of the BSBD model.

See data sources for more details.

How this data set is produced

The source data is gridded using the method "Stacked continuous curvature splines in tension". Basically it works like this:

The source data density grid displayed in the map shows which gridding resolution each cell originates from. Dark green cells have been gridded at the native resolution (500m), whereas yellow, orange and red cells originate from coarser grids. A little simplified, the source data density grid shows approximately the distance between the source data points used for the compilation.

Color scale


>500m 500m – 250m 250m – 100m 100m – 25m 25m – 0m 0m
−500m −250m −100m −25m 0m

Source data density

500m 1km 2km 4km 8km 16km 32km 64km
Hatched areas are based upon interpolated, gridded source data, which makes the source data density plot misleading (i.e. looking too good).

Downloadable data formats

ASCII .xyz

Space delimited XYZ-ASCII Format with the columns longitude, latitude and depth in meters. Latitude an longitude are formatted in decimal degrees with decimal point. The records are separated by Unix style end-of-lines.

Arc ASCII grid

Standard text-based grid format developed by ESRI. You can find a format description on Wikipedia. The file extension is .grd and is supported by Arc-Map version 9.6 and later. For support in earlier versions of Arc-Map please change the file extension to .asc after download.

32bit floating-point GeoTIFF

Single-channel GeoTIFF data, featuring depth as 32bit floating point numbers.


PNG image, showing a colored and shaded relief of the BSBD model as well as a shaded relief of land elevations. You should be able to view these files in your web browser and most image viewing programs.


3-channel RGB GeoTIFF image, showing a colored and shaded relief of the BSBD model as well as a shaded relief of land elevations.

Positioning, projections and vertical reference

Positioning and projections

The map view is presented in EPSG:3035 ETRS89/LAEA projection. All data downloaded from the map comes in unprojected geographic (latitude/longitude) coordinates in EPSG:4258 referencing to ETRS89.

The OGC services provide additional spatial reference systems. See the GetCapabilities output of the WMS for an authoritative list.

Vertical reference

The vertical reference in this project is EPSG:5730, EVRF2000. The horizontal and vertical combination is also referred to as EPSG:7409.

More information

See the spatial reference systems page.


INSPIRE compliant metadata records for the Baltic Sea Bathymetry Database is available at: