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.

Seamless Shom nautical charts - West Africa is a product composed of digital images taken from Shom nautical charts, with no additions, legends or georeferencing information. At a given scale, it is possible to view only the maps with a scale that allows a correct display. The footprint of all the maps composing this product are shown. Unless exceptional circumstances apply, this product is updated on a monthly basis and the modified grid squares are re-published, replacing the previous versions. All corrections, publications and editions with an effect on the reference nautical charts are taken into consideration.

Seamless Shom nautical charts - West Africa - EAtHC is a product composed of digital images taken from Shom nautical charts, with no additions, legends or georeferencing information. At a given scale, it is possible to view only the maps with a scale that allows a correct display. The footprint of all the maps composing this product are shown. Unless exceptional circumstances apply, this product is updated on a monthly basis and the modified grid squares are re-published, replacing the previous versions. All corrections, publications and editions with an effect on the reference nautical charts are taken into consideration.

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

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.