All systems, which are not tested to show compliance with the ECDIS Performance Standards, can be generically designated as ”Electronic Chart Systems” (ECS).An ECS may be able to use either official ENCs, RNCs or other chart data produced privately and could have functionality similar to ECDIS.

Some ECS equipment manufacturers also produce vector and raster data to use in their products. These suppliers have been producing private chart data for a number of years and have established themselves in the market. They were the pioneers and have established the idea and the use of electronic chart systems on vessels. Their charts are derived from Hydrographic Office paper charts or Hydrographic Office digital data.

Hydrographic Offices do not take any responsibility for the accuracy or reliability of privately produced charts.

Where the vessel operates with ECS, the paper chart remains the official basis for navigation onboard. The vessel must retain and use a full folio of up-to-date paper charts onboard, regardless of the type of electronic charts used.