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).

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.

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 bathymetric DEM for the coasts of New-Caledonia with a resolution of 0.001° (~ 100 m) was prepared in the framework of a Shom-IRD partnership as part of the TSUCAL project. The DEM covers the basin from New Caledonia in the west to the Vanuatu archipelago in the east. The DEM is designed to be used in hydrodynamic models in order to improve the pertinence of the Waves-Submersion monitoring programme.

Bathymetric datasets, collected between 1970 and 1990, are mainly acquired with single-beam echosounders. 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 topo-bathymetric DEM of Tahiti 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 Tahiti 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).

The bathymetric DEM for the coasts of Guadeloupe and Martinique with a resolution of 0.001° (~ 100 m) was prepared as part of the HOMONIM project. The DEM covers some of the Lesser Antilles islands, from Anguilla in the north to Saba in the south. The model ranges off-shore to a depth of 3275 m. The DEM is designed to be used in hydrodynamic models in order to produce high-precision forecasts for coastal water levels and sea conditions and therefore improve the pertinence of the Waves-Submersion monitoring programme.

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 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 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.