• Only the binary implementation of S-57 is supported. The ENC specification only allows the binary implementation for storage of ENC data.

  • Not all data-set-descriptive records are taken into account. Units are not decoded, for example. Only WGS 1984, WGS 1972 and European 1950 are supported. See S-57 specification, sections 1.2.2, 3 and 7.3.

  • Decoding of data dictionary records is not supported. The IHO Object Catalogue is used exclusively. See S-57 specification, sections 1.2.4 and 7.5.

  • Faces are not decoded. Faces are only used when the spatial data are encoded using the full topology model; most of the data sets available today are not yet using this model. Section 2.2.1 of the S-57 specification gives a detailed overview of the available vector models.

  • The following spatial record fields are not decoded: ARCC, AR2D, EL2D, CT2D. See S-57 specification, sections and 7.7.1.


  • Arcs inside symbols are not decoded. The currently supported version of the Presentation Library (v3.3) does not make use of arcs in its symbol definitions. See S-52 specification, article 5.

  • Overradar flag and viewing group are not taken into account yet. The first specifies whether objects should be shown on top of radar or not, the second allows a fine-grained control of which features appear on the display. See S-52 specification, section and section

  • "IHO ECDIS Presentation Library, Users' Manual, PART II: Mariners' Navigational Objects". Representation and symbolization of these objects are the responsibility of the developer.