ECDIS – A computer-based navigation information system capable of continuously determining a vessel's position in relation to land, charted objects, aids-to-navigation, and unseen hazards. When provided with adequate back-up arrangements, it is capable of meeting the chart requirements called for in the 1974 Safety of Life-at-Sea (SOLAS) Convention. As an automated decision aid, it also assists the mariner in route planning and route monitoring, and by displaying additional navigation and chart-related information (e.g., radar/ARPA, AIS, water levels, current flow, and weather.

ECS - Electronic chart systems. A collective term for systems which can display various types of electronic charts, perhaps even ENC, but which do not meet the IMO and IEC standards for an ECDIS. ECS therefore do not meet the relevant SOLAS chart carriage requirements.

IENC – Inland ENC. A digital database, standardized as to content, structure, and format for use with electronic charting systems in navigable rivers and waterways. Based on the ENC Product Specification contained in IHO S-57 Edition 3, a Inland ENC contains all the chart and hydrographic information considered necessary for safe navigation on the rivers and inland waterways under the responsibility of the USACE – New Orleans District.

IHO – International Hydrographic Organization. An intergovernmental consultative and technical organization supporting the safety in navigation and the protection of the marine environment. (www.iho.shom.fr )

River ENC – Inland ENC developed for use in inland rivers and waterways.

S-57 – An international standard adopted by the International Hydrographic Organization (IHO) used for the exchange of digital hydrographic data between government agencies, and for the distribution of digital data and products to manufacturers, mariners, and other data users. The most significant digital product being delivered in S-57 format is the Electronic Navigational Chart (ENC). An IHO S-57 ENC is specified in the IMO Performance Standards for ECDIS.

See Rivers Glossary for useful definitions of river structures and features.

Page last updated June 11, 2003