IHO S-57 (ENC) Translation

IHO S-57 format is a vector interchange format used for maritime charts. The only currently common profile is known as ENC (Electronic Nautical Chart). The format is promulgated by the IHO (International Hydrographic Organization).

I have written an OpenSource library to read S-57 files that is built on my OpenGIS inspired OGR Simple Features library. Currently the source is not separately available, but it may be downloaded as part of the OGR (and GDAL) source, and is found in the gdal/ogr/ogrsf_frmts/s57 directory.

Downloading Software

Ready to use S-57 software for windows and Linux can be found in the FWTools suite. In particular the ogr2ogr utility can be used to convert S-57 data into other formats such as shapefiles. For instance, if you were to do the following you would translate all the features types of us5tx51m.000 into Shapefiles (in the directory out) with one shapefile per feature type.

C:\Program Files\FWTools0.9.5> ogr2ogr -skipfailures out us5tx51m.000

Be aware that the above will produce a variety of errors and warnings about feature types with mixtures of geometry types (not supported by the shapefile format), and the fact that some attributes (such as color lists) are dropped when writing to Shapefile.

Sample Datasets

NOAA ENCs direct from NOAA.
us5tx51m.zip: One locally hosted US file.

NOTE: I used to have more pointers here, but people keep moving stuff around so the old links that no longer work have been removed. Feel free to suggest pointers for S-57 data samples I can add.

Resources

S-57 OGR Online User Documentation
s57objectclasses.csv, s57expectedinput.csv, and s57attributes.csv files contributed by Rodney Jensen are the basis of classifying S-57 object classes properly.
Universal Systems S-57 Support Page including information on how to subscribe to an S-57 mailing list.
Online S-57 Object Catalog provided by Universal Systems.
Grab SeeMyENC from SevenCs.
My ISO 8211 Library.
Open ECDIS Forum.
NOAA ENC Charts for US regions.

Credits

I would like to thank the following for their assistance in writing and debugging my S-57 source code.

Safe Software who funded my implementation of the reader, including the underlying ISO8211 library, and permitted me to release it as Open Source.
Rodney Jenson (rodney at online.no) who wrote the csv files with all the object classes and attributes for S-57, and provided moral support.
Paul Hardy and others from LaserScan who provided background information for me on the S-57 format.
Martin Daly of Cadcorp who provided sample files and analysis of some bugs.