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 066 Nouvelle Caledonie - La Poya (ZH) which is assimilated to LAT. Data are corrected for sound velocity variations. Data are acquired during the campaign S198803000 (http://dx.doi.org/10.17183/S198803000). // Instruments: Sondeur DESO 20 // Number of soundings: 1673 // DOI: http://dx.doi.org/10.17183/LOTS_BATHY#S198803000-1

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 146 France - Camaret (ZH) which is assimilated to LAT. Data are corrected for sound velocity variations. Data are acquired during the campaign S196900100 (http://dx.doi.org/10.17183/S196900100). // Instruments: Sondeur KELVIN-HUGHES // Number of soundings: 5447 // DOI: http://dx.doi.org/10.17183/LOTS_BATHY#S196900100-10

Product replaced by Litto3D - Brittany 2018-2021. https://services.data.shom.fr/geonetwork/srv/fre/catalog.search#/metadata/BATHYMETRIE_LITTO3D_BZH_2018_2021.xml

For more than 200 years, Shom has maintained a bathymetric knowledge base enriched by surveys and campaigns over time. They are composed of point clouds which have a density higher than those shown on nautical charts. Datasets are stored in the Shom Bathymetric Database (BDBS) which is a source to describe seabed reliefs. These data are useful for many applications as oceanographic modeling or seabed exploitations. The bathymetric datasets have been granted a distribution agreement. Data are not modeled. This modeling is left to the initiative of the customers. In other terms, they are point clouds data on the field, treated to the hydrographic standards in force at the time of their acquisition and validated. The product is composed of bathymetric datasets which cover the entire French Exclusive Economic Zone (EEZ) as well as international waters. The cover and its cutting are available on the Shom portals (data.shom.fr). Data positions are provided in geographic coordinates reported to the World Reference Geodetic System WGS84. They are vertically referenced to the zero of the soundings reduction which is usually associated to the hydrographic Chart Datum of the corresponding area. For depths up to 50m, the data vertical accuracy varies from 30cm to 1m and the planimetric accuracy varies from 1 to 20m. Beyond, in deep seas, the vertical accuracy is mainly of the order of 1 to 2% of the bottom depth. Sometimes, it is higher depending on the technology used.

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.

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

Bathymetric datasets, collected between 1990 and 2005, are digital data controlled and qualified. They are acquired with single-beam echosounders and the first generations of multi-beam echosounders.

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).

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 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 Montserrat in the north to Sainte-Lucie in the south. The model ranges off-shore to a depth of 5800 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.