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.

Litto3D provides 3D, continuous sea-land description of French coastal areas. Data is acquired by airborne topo-bathymetric LiDARs. Litto3D products come in 3D point clouds and digital terrain models formats. The product "Litto3D - Nouvelle-Aquitaine 2020-2022" covers the geographical area from the Charente-Maritime to the Spanish border. For the maritime part, the data produced by Shom extend offshore down to signal extinction, approximatively 20 depth when environmental conditions are optimal. On land, the data are truncated at a limit that ensures the product retain its coastal character.

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 /> 24/09/2026 version <br />

Weather forecasting models are used to show atmospheric conditions by computing changes in meteorological parameters on a 3D atmospheric grid model. Physical laws are used to determine behaviour: fluid mechanics, variation in water phase, turbulence, radiation, and atmospheric interaction with space, the continents and the oceans. The initial conditions are determined by assimilating variational data including a large volume and wide variety of in situ observations obtained from remote detection systems. The weather forecasts available on data.shom.fr only contain "wind at 10m" and "atmospheric pressure at sea level" parameters. A land/sea mask is then applied to exclude non-maritime forecasts. These forecasts are taken from 2 different types of models: ARPEGE for world and European scale input (0.5° to 0.1° resolution) and AROME for mainland France (1.3 km resolution). ARPEGE is a global hydrostatic spectral model, with variable horizontal resolution (centred on France), vertical finite element modelling and hybrid vertical coordinates. ARPEGE is an integral part of the Arpège-IFS software package, designed, developed and maintained by Météo-France in cooperation with ECMWF (European Centre for Medium-Range Weather Forecasts - http://www.ecmwf.int/). AROME is a non-hydrostatic spectral model for weather forecasts in mainland France, with finite difference modelling for vertical input and hybrid coordinates. AROME was developed by Météo-France thanks to close national (CNRS) and international (CEPMMT, Aladin, Hirlam) cooperation programmes on the basis of the Méso-NH research model and the dynamic core of the Aladin model.

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.

Bathymetric datasets are an extraction of surveys belonging to the Shom public database. For depth up to 50m, the vertical precision of soundings varies from 30cm to 1m and the horizontal precision varies from 1 to 20m. In deep ocean, the vertical precision is mainly around 1 or 2% of the bottom depth. It is sometimes more, it depends on the technology used. The data are referenced to ZH which is assimilated to LAT. Data are corrected for sound velocity variations. <br /> October 27 2025 version

The “Maximum tidal current speeds for mean spring tides” product provides information on the maximum speeds reached by tidal currents on mainland French coasts (English Channel and the Atlantic). These data can be used to identify areas subject to the strongest surface tidal currents and to characterize the maximum current intensity reached during a tidal cycle under mean spring tide conditions. The data are provided in shapefile format, with polygons associated with maximum current speed values, without any temporal or directional information. The values are expressed in knots.

The "Sovereignty and jurisdiction maritime spaces of France" product contains the areas of sovereignty and jurisdiction maritime spaces of France all around the world.<br /><br /> It is constituted of 2D areas objects split into four categories :<br /> - the territorial sea (from baselines to a distance of 12 nautical miles or to maritime boundaries with neighbouring countries);<br /> - the contiguous zone (from 12 nautical miles to 24 nautical miles from the baselines or to maritime boundaries with neighbouring countries);<br /> - the exclusive economic zone (EEZ) (from 12 nautical miles to 200 nautical miles from the baselines or to maritime boundaries with neighbouring countries);<br /> - the continental shelf over the 200 nautical miles limit (from 200 nautical miles from the baselines to the limits recommended by the Commission on the Limits of the Continental Shelf (CLCS) or to the maritime boundaries with neighbouring countries).<br /> Internal waters, which constitute a space of sovereignty beyond the baselines, are not included in the "Sovereignty and jurisdiction maritime spaces of France" product.<br /> The "Sovereignty and jurisdiction maritime spaces of France" product may not be considered as an enforceable right. Only the “Maritime limits and boundaries” product, that can be displayed and interrogated on the website data.shom.fr (maritime boundaries category) and also downloaded on the French national portal of maritime limits (https://maritimelimits.gouv.fr), may be considered so.<br /><br /> December 2022 version.

The Tidal stream atlas netcdf product provides tidal current data for an area stretching from the French coast, covering The English Channel and the Bay of Biscay. The product consists of gridded files with different spatial resolutions. The U and V velocities of the tidal currents depend on the tidal conditions considered at mean neap and spring tidal rates. The data are provided in m/s for the surface layer. The times are given in relation to high tide at the reference port chosen in the area and are provided from 6 hours before to 6 hours after that reference.