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 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 “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.

Marine toponymy data layer obtained from French ENC and created using the S23 (4th edition, June 2002). Note: The usual Sea of Japan designation does not imply taking a stand in the dispute between Korea, which names this sea "East Sea", and Japan, which names it "Sea of Japan".

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

Geographic information layer including the Saline limit of waters - 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

"Traffic Separation Schemes" product contains a description of TSS in French maritime spaces. A TSS is a routeing measure aimed at the separation of opposing streams of traffic by appropriate means and notably by the establishment of traffic lanes. The measures taken aim at improving navigation safety in areas where navigation is threatened by the density of traffic associated with various natural difficulties. Several classes of objects constitute this product, the acronyms used are those of IHO standard S-57: - Traffic separation scheme lane part (TSSLPT): area of a traffic lane in which the direction of flow of traffic is uniform; - Traffic separation scheme boundary (TSSBND): outer limit of a traffic lane part or a traffic separation scheme roundabout; - Traffic separation line (TSELNE): common boundary between two traffic lanes, or between one traffic lane and one inshore traffic zone; - Traffic separation zone (TSEZNE): separation areas between two traffic lanes, or between one traffic lane and one inshore traffic zone, or to the central area of a roundabout; - Inshore traffic zone (ISTZNE): area between the landward boundary of a traffic separation scheme and the adjacent coast; - Precautionary area (PRCARE): area, within defined limits, where ships must navigate with particular caution, and within which the direction of traffic flow may be recommended; - Deep water route part (DWRTPT): sections within which the flow of traffic either follows one defined direction for one-way traffic, or follows one defined direction and its reciprocal for two-way traffic. A deep-water route is a route in a designated area within defined limits which has been accurately surveyed for clearance of sea bottom and submerged obstacles to a minimum indicated depth of water; - Two-way route part (TWRTPT): sections within which traffic flows in two directions along one bearing and its reciprocal. These route parts are generally two-way, but some may be restricted to one-way traffic flow; - Radio calling-in line (RDOCAL_lne) : positions at which vessels are required to report to a traffic control centre.

"Harbour Information" product contains 13 object classes, the acronyms used are those of IHO standard S-57 - International Hydrographic Organization – (https://iho.int/): - Berth (BERTHS): place in which a ship is moored at wharf - Isolated building localizing a harbour office (BUISGL) - Checkpoint (CHKPNT) - Crane (CRANES) - Floating dock (FLODOC): floating structure of one or more sections which can be partly submerged by controlled flooding to receive a vessel, then raised by pumping out the water so that the vessel's bottom can be exposed for maintenance. - Gridiron (GRIDRN): structure in the intertidal zone serving as a support for vessels at low tide to permit work on the exposed portion of the vessel's hull. - Harbour area (HRBARE) : administrative area of a port, including all docking and handling facilities, as well as short-term storage facilities. - Harbour facility (HRBFAC) - Hulk (HULKES) : hull of a wrecked or condemned ship, from which the fittings and superstructure have usually been removed, which is moored in a permanent position or grounded. - Oil barrier (OILBAR) - Pilot boarding place (PILBOP) - Rescue station (RSCSTA) - Small craft facility (SMCFAC) 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/).