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

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..

Geographic information layer including the Limit of maritime affairs - mainland France, French Guiana, Martinique and Guadeloupe. This layer must be considered as an initial version to be validated locally by the competent services. Shom actively seeks out any information which could complete and improve the precision of this layer. The streams and rivers listed correspond to those mentioned in the applicable regulations and/or by a competent Government service. An inventory of existing legal and geographic information was drawn up prior to production in the form of an enquiry targeting services during the second half of 2014. The source legal text and a summary of digital conversion processes is available for each boundary proposed.Updated july 2018

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

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

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.

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 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.

The Tidal stream atlas netcdf product – The Bay of Biscay provides tidal current data for an area stretching from Brittany to the northern coast of Spain. The product consists of a unique gridded file with 2 km spatial resolution covering the Bay of Biscay. 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.