IHO

The International Hydrographic Organization (IHO) is an

intergovernmental consultative and technical organization working to

support the safety of navigation and the protection of the marine environment.

The object of the Organization is to bring about :

a) The coordination of the activities of national hydrographic offices ;

b) The greatest possible uniformity in nautical charts and documents ;

c) The adoption of reliable and efficient methods of carrying out and

exploiting hydrographic surveys ;

d) The development of the sciences in the field of hydrography and the

techniques employed in descriptive oceanography.

S-57 is the International Hydrographic Organization Transfer Standard for Digital

Hydrographic Data. It consists of a feature dictionary, a data model, and an exchange

format called DX-90. S-57 is an object-based data structure; its feature dictionary

describes the geometry and attributes of all features that may appear on an electronic

navigation chart (ENC).

As part of the regular update activity by the DGIWG, Part 4 of DIGEST (FACC) is

being incrementally updated to achieve greater harmonization with S-57. This

activity resulted in DIGEST 2.0 Amendment A.

See: http://www.iho.shom.fr/ Also: http://www.universal.ca/S-57/s57_enc_catalog.html