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. The vertical reference for this product is the Lowest Astronomical Tide (LAT).

The coastal topo- bathymetric DEM of the port of Saint-Malo and its surroundings with a resolution of 0.00005° (~ 5 m) was prepared as part of the PAPI Saint-Malo. It covers the city of Saint-Malo and its surroundings, from the tip of Décollé in the west to the tip of Varde in the east. 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 data layer contains the current status of hydrographic knowledge expressed in terms of CATZOC (category of zone of confidence, cf. https://iho.int/uploads/user/pubs/standards/S-67/S-67%20Ed%201.0.0%20Mariners%20Guide%20to%20Accuracy%20of%20Depth%20Information%20in%20an%20ENC_EN.pdf), as well as the target defined by the national hydrography program.

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 Mean Sea Level (MSL).

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).

Litto3D is a unique and continuous land-sea database which provide 3D models of french coastal areas. Surveys are carried out by airborne lidar bathymetry over the sea side and airborne lidar topography over the land up to 2km inland. Litto3D digital models are available in two formats: a set of 3D points and a digital terrain model. The product "Litto3D - Brittany 2018-2021" covers the coastline and islands of Côtes d'Armor, Ille-et-Vilaine and Morbihan departments.

The high resolution Coastline corresponds to the Highest Astronomical Tide (HAT) with a tidal coefficient of 120 and in normal weather conditions (no sea breeze and mean atmospheric pressure of 1013 hPa). The high resolution coastline is available in french subantarctic islands (984).

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 bathymetric DEM was produced using the bathymetric and topographic data acquired between 2012 and 2015 by Shom and the PASSION programme team. The extent of the 100 m coastal grid covers an extended area around Passion Island – Clipperton, Mount Queiros, Mount Cermeno, and adjacent shallow waters. Passion island - Clipperton, in the eastern Pacific Ocean, is a remote uninhabited atoll over 5,000 km from Tahiti in French Polynesia and over 1,000 km from the Mexican coasts. Passion island is the highest point on the Clipperton ridge, and the only location above water level. This is the only coral atoll in the eastern Pacific in the northern hemisphere, at a longitude of W 109° and a latitude of N 10°.

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).