These maps are prepared on the basis of vector-based mapping data (IHO S-57 format) including the detailed description of each object (beacons, wrecks, submarine cables, regulated zones, survey systems, etc.). These maps are the digital equivalent of printed nautical charts.

The georeferenced digital image solution for the nautical chart is a digital conversion of the corresponding printed nautical chart produced by Shom or its legends, with georeferencing indications and including miscellaneous text.

Non-georeferenced digital images in JPEG2000 format from former hydrographical survey fair sheets obtained from Shom's historical archives.