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

Litto3D 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 update of the coastal topo-bathymetric DEM of the Gironde estuary - downstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the downstream part of the Gironde estuary, from Pauillac to its mouth. It is complementary to the DEM covering the upstream estuary. The DEM is intended to be implemented in hydrodynamic models in order to produce forecasts as accurate as possible of water heights and sea states at the coast to improve the relevance of the Wave-Submergence Vigilance. This product is available with either the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical reference.

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 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.

The Histolitt® coastline corresponds to the high tide line with an astronomic tidal coefficient of 120 and in normal weather conditions (no sea breeze and no low pressure systems likely to raise sea level). The Histolitt® coastline models this theoretical input as a series of 2D polylines. In mainland France, it is recommended to use the land-sea limit product which replaces this Histolitt® coastline. There is no land-sea limit in the French overseas areas for the moment.

The coastal topo- bathymetric DEM for the coasts of the straight of Pas-de-Calais with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project. The DEM covers the eastern Channel and southern North Sea, including the French coast of the Nord - Pas-de-Calais administrative department and part of the British coast, in the county of Kent, and the south part of the Thames estuary up to Rye. 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.

The coastal topo-bathymetric DEM of Moorea with a resolution of 0.0002° (~ 20 m) was produced by the Shom for Météo-France (Inter-regional Direction in French Polynesia). This DEM covers the Moorea lagoons down to the 100 m isobath, in order to meet the need for modeling marine submersions in French Polynesia. It complements the bathymetric DEM of Tahiti and Moorea, with a resolution of 0.001° (~ 100 m). This product is available at different vertical references, either the lowest astronomical tide (LAT) or the mean sea level (MSL).

Litto3D Marine Part is an intermediate product of the Litto3D product containing only marine data.Litto3D 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 coastal topo-bathymetric DEM of Moorea with a resolution of 0.0002° (~ 20 m) was produced by the Shom for Météo-France (Inter-regional Direction in French Polynesia). This DEM covers the Moorea lagoons down to the 100 m isobath, in order to meet the need for modeling marine submersions in French Polynesia. It complements the bathymetric DEM of Tahiti and Moorea, with a resolution of 0.001° (~ 100 m). The vertical reference for this product is the Lowest Astronomical Tide (LAT).