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.

Bathymetric datasets, collected before 1970, are historical surveys acquired with leadlines (and single-beam echosounders after 1930-1940). Quality controls and qualification, conducted by the Shom, on these datasets are not exhaustive. Datasets may present significant uncertainties and errors may remain.

The coastal topobathymetric DEM of Ré Island's surroundings, with a resolution of 0.00005° (~5 meters), was created by Shom as part of the HOMONIM-3 project. It covers the coast of the municipalities of Ars-en-Ré and Saint-Clément-des-Baleines, extending offshore to a depth of about 20 meters, to the west of the Phare des Baleines lighthouse. This DEM is designed for use in hydrodynamic models to enhance the modeling of coastal processes, particularly forecasting submersion risk. The product complements the coastal topobathymetric DEM of the Pertuis-Charentais, with a resolution of 0.0002° (~20 meters), and the bathymetric DEM of the Atlantic coast, with a resolution of 0.001° (~100 meters). It is available in the vertical reference of the Lowest Astronomical Tide (LAT) or the Mean Sea Level (MSL).

Bathymetric datasets, collected after 2005, are controlled and qualified. They are mainly acquired with multi-beam echosounders.

The update of the coastal topo-bathymetric DEM of the Gironde estuary - upstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the upstream part of the Gironde estuary, from Pauillac to Bordeaux on the Garonne and to Libourne on the Dordogne. It is complementary to the DEM covering the downstream estuary (between Pauillac and the mouth of the Gironde). 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.

Lidar marine product is a unique and continuous land-sea database which can provide 3D models of the shape and location of french coastal terrain. Surveys are carried out by airborne lidar bathymetry over the sea side and airborne lidar topography over the land side up to 400m inland. This marine product is 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 - upstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the upstream part of the Gironde estuary, from Pauillac to Bordeaux on the Garonne and to Libourne on the Dordogne. It is complementary to the DEM covering the downstream estuary (between Pauillac and the mouth of the Gironde). 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. The vertical reference for this product is Mean Sea Level (MSL).

The bathymetric DEM of Tahiti and Moorea with a resolution of 0.001° (~ 100 m) was produced by the Shom for Météo-France (Inter-regional Direction in French Polynesia). This DEM covers a 10 km radius around the islands of Tahiti and Moorea in order to meet the need for marine submersions modelling in French Polynesia. The vertical reference for this product is the Lowest Astronomical Tide (LAT).

The update of the coastal topo-bathymetric DEM of the Pertuis charentais at a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. The DEM extends from the terrestrial domain to about 60 meters depth over all the pertuis (pertuis Breton, pertuis d’Antioche and pertuis of Maumusson). 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.

The bathymetric DEM of Tahiti and Moorea with a resolution of 0.001° (~ 100 m) was produced by the Shom for Météo-France (Inter-regional Direction in French Polynesia). This DEM covers a 10 km radius around the islands of Tahiti and Moorea in order to meet the need for marine submersions modelling in French Polynesia. This product is available at different vertical references, either the lowest astronomical tide (LAT) or the mean sea level (MSL).