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 “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 /> 05/02/2026 version <br />

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 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 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.

"Regulation - Navigation" product contains 18 object classes, the acronyms used are those of IHO standard S-57 - International Hydrographic Organization – (https://iho.int/): - Anchorage area (ACHARE): an area in which vessels anchor or may anchor. - Anchor berth (ACHBRT): a designated area of water where a single vessel, sea plane, etc. may anchor. - Administration Area (Named) (ADMARE) - Cable area (CBLARE) - Coastguard station (CGUSTA) - Cargo transhipment area (CTSARE) - Distance mark (DISMAR): mark indicating the distance on canals or rivers. - Dumping ground (DMPGRD): sea area where dredged material or other potentially more harmful material e.g. explosives, chemical waste, is deliberately deposited. - Fairway (FAIRWY): part of a river, harbour etc. where the main navigable channel for vessels of larger size lies. It is also the usual course followed by vessels entering or leaving harbours and sometimes called "ship channel". - Ice area (over land or water) (ICEARE) - Local magnetic anomaly (LOCMAG): anomaly of the magnetic field of the earth, extending over a relatively small area, due to local magnetic influences. - Marine farm/culture (MARCUL) - Navigation line (NAVLNE): a line generally passing through two clearly defined charted landmarks, and along part of which a vessel can approach safely. - Pipeline area (PIPARE) - Recommended track (RECTRC): track of undefined width, recommended to all or only certain vessels. - Restricted area (RESARE): specified area designated by an appropriate authority within which navigation is restricted in accordance with certain specified conditions. - Sea-plane landing area (SPLARE) Detailed definitions of each of these object classes can be found in the S-57 standard (https://iho.int/en/standards-and-specifications). An online catalog is available at http://www.s-57.com/. Some of the symbols used for display on data.shom.fr portal have been adapted from icons from the OpenSeaMap open library (https://github.com/OpenNauticalChart/). For reasons of readability, not all the characteristics of the objects are systematically displayed. All available information can be consulted by querying this layer.

The coastal topo-bathymetric DTM of the Arcachon basin and its surroundings at a resolution of 0.0002° (~ 20 m) was produced as part of the HOMONIM project. The DTM covers the coastline of a part of the Gironde department, from the Carcans and Hourtin ponds in the North, to the Cazaux and Sanguinet lakes in the South. It covers the entire Arcachon basin and extends offshore to about 40 m depth. The DTM is intended to be implemented in hydrodynamic models in order to produce accurate forecasts of water heights and sea states at the coast and to improve the French storm surge warning system. This product is available with the Lowest Astronomic Tide (LAT) or with the Mean Sea Level (MSL) as a vertical datum.

Tidal ranges on the French coasts of the Channel and the Atlantic for a coefficient of 20 : minimum tidal range for average atmospheric conditions..