The "Magnetic Stations" product contains measurements from magnetic reference stations deployed by the French Hydrographic and Oceanographic Service (SHOM) near marine magnetic survey areas. Measurement files are available by station and by year. These magnetic reference measurements correct marine measurements for diurnal and high-frequency variations in the Earth's magnetic field.

Lidar marine part is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh. The product Tahiti 2015 V. 20160630 corresponds to the zone: North West of Tahiti.

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

This service allows users to view surface tidal current predictions calculated from the analysis of a high-resolution hydrodynamic simulation projected onto a 500 m grid. This service was built by Shom and funded by French CCI Métropolitaine Bretagne Ouest in the frame of the Atlantic Blue Port project of <a href="https://www.atlanticarea.eu" target="_blank">Interreg Atlantic Area</a> european program.

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 – The Channel provides tidal current data for an area stretching from the coast of Flanders east of Dunkirk to Brest. The product consists of a unique gridded file with 2 km spatial resolution covering the Channel. 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.

French Ministry of Culture / DRASSM – Shom The product "Limit of preventive archeology licence fee" contains the limits for the preventive archeology licence fee (1 nautical mile) as defined in the French Heritage Code. This limit is managed by the Department of Underwater Archeological Research (DRASSM) of the Ministry of Culture. This limit, defined by the Heritage Code at 1 nautical mile from the low-water line, permits to delineate the areas where the licence fee for preventive archeology at sea is applied. In Mainland France in the Gironde estuary, the limit for the preventive archeology licence fee is stopped by the crosswise limit of the sea as defined by the decree of 26 August 1857. In French Guiana, the limit for the preventive archeology licence fee is stopped in Maroni and Oyapock rivers by the crosswise limits of the sea respectively defined the order of 30 January 1991 and the order No 863 of 26 May 1986, until meeting the land boundary which delineates the rivers with the neighbouring States. The product "Limit of preventive archeology licence fee" is to use in addition to the digital product “Maritime Limits and Boundaries” of Shom (French: “Délimitations maritimes”) which represents the limits of the French maritime spaces of sovereignty or jurisdiction through the World. The product “Maritime Limits and Boundaries” (French: “Délimitations maritimes”) can be viewed on data.shom.fr (Maritime boundaries Category) and downloaded on the French national portal of maritime limits (https://maritimelimits.gouv.fr).

The Tidal stream atlas netcdf product – Northern Brittany provides tidal current data for an area stretching from Tregastel at the east of the area to Porsguen at the west. The product consists of two gridded files with different spatial resolutions covering the Northern Brittany area (overall view at 500 m) and the geographical area of the port of Roscoff (250 m). 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.

This service allows users to view surface tidal current predictions calculated from the analysis of a high-resolution hydrodynamic simulation projected onto a 30 m grid. This service was built by Shom and funded by French CCI Métropolitaine Bretagne Ouest in the frame of the Atlantic Blue Port project of <a href="https://www.atlanticarea.eu" target="_blank">Interreg Atlantic Area</a> european program.

"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.