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 20 : minimum tidal range for average atmospheric conditions..

The "Military practice areas" product contains vector data in the form of 2D surface objects describing the military practice areas in the France sector represented on Zonex variants of nautical charts. This is the S-57 MIPARE object class (military practice areas): maritime zone within which military, naval or air exercises can take place.

RasterMarine is a series of digital images taken from nautical charts, with no additions, legends or georeferencing information. The RasterMarine range is available at five sets of scales: - RasterMarine 20 1: 20,000 - RasterMarine 50 1: 50,000 - RasterMarine 150 1: 150,000 - RasterMarine 400 1: 400,000 - RasterMarine 1M 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 and editions with an effect on the reference nautical charts are taken into consideration. <br /> 13/03/2025 version <br />

These maps are prepared on the basis of vector-based mapping data (IHO S-57 format) including the detailed description of each object (beacons, wrecks, submarine cables, regulated zones, survey systems, etc.). These maps are the digital equivalent of printed nautical charts.

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.

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.

The « Maritime Spatial Planning » product contains 2D areas vector objects representing the extent of the maritime spatial plan (« MSP Spatial Plan » layer) and the extent of the corresponding vocation zones (« MSP Zoning Element » layer), defined in each strategic façade document.

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