S-57 (ENC) Hydrographic Data Reader

The S-57 Reader module provides FME with access to data in International Hydrographic Organization (IHO) S-57 formatted file sets.

While any S-57 dataset should be supported, this reader has only been fully tested with S-57 Electronic Navigational Chart (ENC) profile products. Note that S-57 Editions 3.0 and 3.1 are supported.

Note: This chapter also contains information applicable to the Additional Military Layers (AML) reader.

S-57 (ENC) Hydrographic Data System Requirements



Operating System


FME Desktop License

FME Server

FME Cloud





Available in FME Professional Edition and higher



64-bit: Yes




The S-57 format is a standard published by IHO. More information can be found in the IHO Publications S-57 Component Documents.

Some aspects of an S-57 transfer, such as data quality information, is not accessible via the S-57 reader, however, a user well-versed in the S-57 format can extract it using the ISO8211 reader.

Reader Overview

The S-57 Reader module produces FME features for all S-57 features in one or more related S-57 data files. An S-57 dataset can be an S-57 catalog file (in which case, all files referred to from the catalog are selected), or an individual S-57 data file.

S-57 feature objects are translated into FME features. S-57 geometry objects are automatically collected and formed into geometries on the features. Geometry objects are not separately accessible with the S-57 reader.

The reader supports S-57 update files. S-57 update files contain information on how to update a distributed S-57 data file. Update files have a file extension of 001, 002, etc.


Depth soundings are handled somewhat specially in the S-57 format to efficiently represent the many available data points. In S-57, one sounding feature can have many sounding points.

The FME S-57 reader splits each sounding point into its own feature type, SOUNDG feature, with an s57_type of s57_point3d.

All soundings from a single feature record have the same AGEN, FIDN, FIDS, and LNAM values.