This product shows the international distribution of types of tides. Four types of tides exist, and are classified based on the number and height of high and low waters each day: semi-diurnal tide: two high tides and two low tides with approximately the same height are recorded each day. Mixed tides with diurnal inequality: two high and low tides are recorded daily (just like with semi-diurnal tides), however the heights of the high and low waters vary significantly over the same day. Diurnal tides: one single high tide and one single low tide are recorded each day. Composite: tides can be diurnal or semi-diurnal or mixed.

Digital Surface Models (DSMs) of the study area were generated by drones on 19 September 2024 and 18 September 2025. Each pixel represents the elevation value of the terrain at the time of the survey. These DSMs were generated from 895 (2024) and 1,282 images (2025), captured at an altitude of 120 (2024) and 100 meters (2025) using the DJI Mavic 3E RTK and Mavic 3M RTK drones, with ground resolutions of 3.19 (2024) and 2.63 cm/pixel (2025). The surveyed area covers approximately 1 km². The DSMs were resampled to a resolution of 20 cm. The vertical coordinate system used is NGF IGN69.

The multispectral images of the study area were acquired by drone on 18 September 2025 using the DJI Mavic 3M RTK. The orthomosaic was generated from 5,128 images across five spectral bands (Green, Red, Red Edge, Near-Infrared (NIR), and Alpha), captured at an altitude of 100 meters (2025). The ground resolution achieved was 4.568 cm/pixel, covering a surveyed area of approximately 0.94 km². The Digital Surface Models (DSMs) were resampled to a resolution of 10 cm.

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.