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.

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.

Non-georeferenced digital images in JPEG2000 format from former hydrographical survey fair sheets obtained from Shom's historical archives.

"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.

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.

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

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.

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.