Better understanding of lagoon processes is a primary necessity in order to monitor pressures and stress due to seasonally and anthropological effects or extreme weather events. It, therefore, leads to the needs for numerical models which are requiring some initial knowledge as boundary conditions. In that matter, coastal bathymetry is a primary requirement for the resolution of numerical models. The outputs of models are also influenced by the resolution and precision of the bathymetry measurements. Traditionally, this kind of measurements are made by echo-sounder, a type of sonar, measuring water depth from sea surface. Nevertheless, the acquisition process remain expensive regarding the means and time required for the mapping of a defined area. Fur- thermore, this methods are often not achieved on areas with shallow depth where boats can hardly sail . Methods relaying on bathymetric LIDAR from airborne are also possible but still expen- sive. Despite less accurate results, satellite derived bathymetry provide a large scale resolution at lower cost. It however required some specific environmental condition such as clear water, clouds free sky, calm waters and some specific sensor conditions such as good penetrating abilities of its wavelength or a zenith angle of view of the sensor.