BSB -- Maptech/NOAA BSB Nautical Chart Format

Driver short name


Driver built-in by default

This driver is built-in by default

BSB Nautical Chart format is supported for read access, including reading the colour table and the reference points (as GCPs). Note that the .BSB files cannot be selected directly. Instead select the .KAP files. Versions 1.1, 2.0 and 3.0 have been tested successfully.

This driver should also support GEO/NOS format as supplied by Softchart. These files normally have the extension .nos with associated .geo files containing georeferencing ... the .geo files are currently ignored.

This driver is based on work by Mike Higgins. See the bsb_read.c files for details on patents affecting BSB format.

It is possible to select an alternate color palette via the BSB_PALETTE configuration option. The default value is RGB. Other common values that can be found are : DAY, DSK, NGT, NGR, GRY, PRC, PRG...

NOTE: Implemented as bsbdataset.cpp.

Driver capabilities

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)


The following metadata items may be reported:

  • BSB_KNP: content of the KNP/ header field, giving information on the coordinate reference system.

  • BSB_KNQ: content of the KNQ/ header field, giving information on the coordinate reference system.

  • BSB_CUTLINE: (starting with GDAL 3.1). When PLY/ header is present, Well-Known text representation of a polygon with coordinates in longitude, latitude order, representing the cutline of the chart.