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.

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 bathymetric DEM of the atlantic facade with a resolution of 0.001° (~ 100 m) was prepared as part of the HOMONIM project. It encompasses part of the North Sea, the Channel and the Bay of Biscay. Offshore, this DTM extends beyond the slope to approximately 4800 m depth. The DEM is designed to be used in hydrodynamic models in order to produce high-precision forecasts for coastal water levels and sea conditions and therefore improve the pertinence of the Waves-Submersion monitoring programme. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

This product includes the boundaries of tidal zones for French Channel, Atlantic and Mediterranean coasts in shapefile format. Information on the characteristics of tidal zones is available as part of the "Maritime Altimetric Reference Values" product.

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 coastal topobathymetric DEM of Ré Island's surroundings, with a resolution of 0.00005° (~5 meters), was created by Shom as part of the HOMONIM-3 project. It covers the coast of the municipalities of Ars-en-Ré and Saint-Clément-des-Baleines, extending offshore to a depth of about 20 meters, to the west of the Phare des Baleines lighthouse. This DEM is designed for use in hydrodynamic models to enhance the modeling of coastal processes, particularly forecasting submersion risk. The product complements the coastal topobathymetric DEM of the Pertuis-Charentais, with a resolution of 0.0002° (~20 meters), and the bathymetric DEM of the Atlantic coast, with a resolution of 0.001° (~100 meters). It is available in the vertical reference of the Lowest Astronomical Tide (LAT) or the Mean Sea Level (MSL).

Shom is the national referent for the level of the sea in situ on all areas under French jurisdiction. In this capacity, he assures under the acronym REFMAR different coordination functions in the collection and dissemination of public data related to water level observations, in order to promote their use in multiple applications within the framework of international recommendations.

Sea bed sediment maps for the 4 marine sub-regions prepared as part of the initial evaluation of the MSFD (Marine Strategy Framework Directive).

The « Maritime Spatial Planning » product contains 2D areas vector objects representing the extent of the maritime spatial plan (« MSP Spatial Plan » layer) and the extent of the corresponding vocation zones (« MSP Zoning Element » layer), defined in each strategic façade document.

Wave forecasting models allow the representation of sea states based on a spectral resolution at the global scale or at the scale of ocean basins. This code calculates the evolution of the sea state by decomposing it into a wave spectrum that propagates in different directions and with different periods. During the propagation, the wave energy is increased or decreased by the effects of wind, breaking waves and energy exchanges between the different components. The wave forecasts available on data.shom.fr are calculated with 2 different types of models: MFWAM for the offshore domain (resolution from 0.5° to 0.1°) and Wavewatch III ® (WW3) for the coastal domain (resolution from 2' to 200m). MFWAM is a sea state forecasting model (wind wave and swell) derived from the third generation WAM code (WAMDI Group, 1988). Wavewatch III ® (WW3) is developed in a collaboration between the United States Weather Service (NOAA/NCEP), Shom, the University of Darmstadt in Germany, and other partners. The forecasts published on data.shom.fr are issued from the parameterization carried out and optimized by the Shom and Météo-France within the framework of the Homonim project (national coastal flood/wave/storm warning system).