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

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.

"Aids ton navigation" product contains a description of landmarks, beaconage or buoyage, in the French Exclusive Economic Zone (EEZ). <br /> June 17 2026 version

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 product "Sea bed sediment 1:50 000" contains 2D surface objects geo-referenced digital data describing the nature of the geological seabed (nature of the sediment, including rock type seabed).

The update of the coastal topo-bathymetric DEM of the Gironde estuary - upstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the upstream part of the Gironde estuary, from Pauillac to Bordeaux on the Garonne and to Libourne on the Dordogne. It is complementary to the DEM covering the downstream estuary (between Pauillac and the mouth of the Gironde). 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 product “Maritime limits and boundaries” (French: “Délimitations maritimes”) gathers all the elements used for the definition of the maritime spaces under the French sovereignty or jurisdiction through the world. Those spaces are defined by the Ordonnance n° 2016-1687 of 8 December 2016 relating to maritime spaces under sovereignty or jurisdiction of the French Republic. This ordonnance is the transcription in the French legislation of the United Nations Convention on the Law of the Sea (UNCLOS) which was signed in Montego Bay (Jamaica) on 10 December 1982 end ratified by France on 11 April 1996. These elements of maritime limits and boundaries come from the limits computed by Shom on the basis of International Law, from the international agreements relating to maritime boundary and the technical conventions ratified between France and other States, from the decisions of international juridical bodies, from the recommendations of the Commission of the Limits of the Continental Shelf (UNO) or from unilateral claims from France in the absence of agreement. The elements are divided into seven themes: 1- Straight baselines 2- Outer limits of the territorial sea (12 nautical miles) 3- Outer limits of the contiguous zone (24 nautical miles) 4- Outer limits of the exclusive economic zone (200 nautical miles) 5- Maritime boundaries established by a bilateral agreement or decided by an international juridical body 6- Maritime boundaries unilaterally claimed by France in the absence of agreement 7- Outer limit of the continental shelf beyond 200 nautical miles December 2022 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.

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