The regional bathymetric Atlantic – Channel – North-Sea DTM has a resolution of 0.001° (~111m). Its geographic coverage includes the Bay of Biscay, the English Channel and a part of the North Sea. The DTM extends from the coast to the continental slope (about of 4800m deep). This DTM is produced in the framework of the HOMONIM project which aims at improving operational forecast capabilities for the national coastal flood warning system. This DTM is offered openly on the Shom diffusion website (http://diffusion.shom.fr/produits/bathymetrie/mnt-facade-atl-homonim.html). http://dx.doi.org/10.17183/MNT_ATL100m_HOMONIM_WGS84

The DTM is a compilation of multibeam echosounder surveys acquired in 2013. The resolution is 1/64 arc-minutes (~30m). Surveys are located on the Capbreton Submarine Canyon (France) with depths from -4.7m to -344.9m. Depths are referenced to the Lowest Astronomical Tide and the coordinates are expressed into the WGS84 reference frame. The surveys which compose the DTM are S201306500-09 and S201306500-11. Data and metadata associated to these surveys are available on the website http://diffusion.shom.fr/pro/lots-bathy.html. The DTM is not to be used for navigation.

Tidal ranges on the French coasts of the Channel and the Atlantic for a coefficient of 95 : tidal range for mean neap tides for average atmospheric conditions..

The “French sub-rectangles of the ICES fishery statistical rectangles” product contains 2D areas vector objects representing a sub-rectangle division of ICES statistical rectangles. Each product polygon belongs to an unique ICES rectangle. This subdivision enables distinction between overlapping areas in two or more EEZs, areas of functional interest and areas of regulatory interest.

The Shom uses a 2D barotropic version of the HYCOM code (https://hycom.org/) to compute water level /surge forecasts (astronomical tides and meteorological surges) for the Atlantic, Mediterranean, Antilles-Guyane and Indian Ocean domains. The configurations use curvilinear grid with resolutions of several km offshore and ranging from 1.5km to around 500m on the french mainland coasts and the Antilles-Guyana coast. A downscaling by nesting allows a resolution of 800m to 200m over the Indian domain. These models have been adapted by the Shom to be operable in coastal areas by taking into account, in particular, the tide and high resolution bathymetry in these areas (from 100m for DTMs of facade to 20m for coastal DTMs) using Litto3D surveys by airborne LIDAR. The models are operated by Météo-France and the Shom in the framework of the HOMONIM project for the coastal flood/wave warning system.

The product contains a description of submarine cables and pipelines brought to the attention of Shom on French areas of responsibility. These are 2D linear objects of the seabed that divide into two categories: • The submarine cables: these are cables placed on the seabed where electricity or information (telecommunication) flows. They represent the vast majority of objects (more than 90%); • Emissaries and submarine pipes: these are pipes that allow the discharge, sampling or circulation of fluids.

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.

The update of the coastal topo-bathymetric DEM of the Pertuis charentais at a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. The DEM extends from the terrestrial domain to about 60 meters depth over all the pertuis (pertuis Breton, pertuis d’Antioche and pertuis of Maumusson). The DEM is intended to be implemented in hydrodynamic models in order to produce forecasts as accurate as possible of water heights and sea states at the coast to improve the relevance of the Wave-Submergence Vigilance. This product is available with either the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical reference.

The “World Seabed Sediment Map” product contains geo-referenced digital data, describing the nature of the sediment encountered in different seas and oceans of the world. The objects are all surface areas and the description of an object includes in particular the nature of the sediment including rock-type bottoms.

RasterMarine is a series of digital images taken from nautical charts, with no additions, legends or georeferencing information. The RasterMarine range is available at six sets of scales: - RasterMarine10 1:10,000 - RasterMarine25 1:25,000 - RasterMarine50 1:50,000 - RasterMarine100 1:100,000 - RasterMarine350 1:350,000 - RasterMarine1M 1:1,000,000. Unless exceptional circumstances apply, the RasterMarine range is updated on a weekly basis and the modified grid squares are re-published, replacing the previous versions. All corrections, publications, editions and suppressions with an effect on the reference nautical charts are taken into consideration. <br /> 19/03/2026 version <br />