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 product contains a description of submarine cables and pipelines brought to the attention of Shom on French areas of responsibility. These are 2D linear objects of the seabed that divide into two categories: • The submarine cables: these are cables placed on the seabed where electricity or information (telecommunication) flows. They represent the vast majority of objects (more than 90%); • Emissaries and submarine pipes: these are pipes that allow the discharge, sampling or circulation of fluids.

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.

Geographic information layer including the Transverse limit of the sea - 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

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

The coastal topo- bathymetric DEM for the coasts of the Saint-Jean-de-Luz bay with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project. It covers Saint-Jean-de-Luz bay and the surrounding area. The DEM is designed to be implemented in the hydrodynamic models of the TANDEM project in order to estimate the coastal effects of tsunamis for the Atlantic and English Channel, where French nuclear power plants have been installed for about 30 years. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

This product includes all Shom digital files for tidal currents on mainland French coasts (Channel and Atlantic coasts) in mesh format. These digital files indicate surface tidal current components, hour by hour and for two typical tidal coefficients (45 and 95) and maximum current speeds for a mean spring tide. Brest is taken as the reference port for viewing purposes. The current points included in these files correspond to the arrows shown on current atlases.

Shom manages a network of permanent digital coastal tide-gauges on French coasts: the RONIM Sea Level Observation Network. Most tide-gauge observatories are partnered with one or more local partners.<br /><br /> Four main types of data are available for download:<br /> - “Raw high frequency" data: raw observations neither validated nor evaluated, obtained directly from the sensor. 1-minute measurement; integration time 15 seconds (on the minute); sampling period: 1 second.<br /><br /> - "Raw non-real time" data: raw observations neither validated nor evaluated, obtained directly from the sensor. 10-minute measurement; integration time 121 seconds (around every 10 minutes); sampling period: 1 second.<br /><br /> - "Validated non-real time" data: observations checked and validated by Shom from the "Raw non-real time" data. 10-minute measurement; integration time 121 seconds (around every 10 minutes); sampling period: 1 second.<br /><br /> - "Validated hourly" data: observations checked and validated by Shom, generated from "Validated non-real time" data. Hourly measurement obtained from the Vondrak filter with triangular weighting. The hourly height cannot be calculated in the event of an observation gap greater than 1.5 hours.

In accordance with decree no. n°2019-165 of 5 March 2019, Shom measures and updates maritime altimetric datums or hydrographic datums for French ports in mainland France and overseas administrative departments and authorities. These datums are provided to allow for standardisation based on legal altimetric datum systems (e.g. IGN69). Shom also disseminates typical tide figures for each port (lowest tide, mean tide, etc.). The Marine Altimetric Reference Value (RAM) product is available for ports in mainland France and for overseas territories with a tidal observatory.