Low-altitude Surveying on the French Mediterranean Coast May 6, 2021 RIEGL tested the performance of its topo-bathymetric airborne laser scanning system in a transition zone context along the French Mediterranean coast. Initially planned as a UAV survey, tests were conducted using a fixed-wing aircraft due to the restrictions placed on operations by the ongoing coronavirus pandemic. The results are encouraging, and the next step will be drone operations in more challenging sea conditions. Topo-bathymetric airborne laser scanning (a field of airborne laser bathymetry, or ALB) is known for its efficiency in seamlessly surveying hybrid landscapes. It is therefore used in hydrography and the maritime cartography of shallow water areas, and has the advantage of capturing topographic and bathymetric data in a single mission. These transition zones, which are difficult to cover by shipborne means or by land-based acquisition only, typically accommodate a large diversity of natural habitats and artificial structures, settlements or infrastructure. Consequently, they carry a high inherent risk due to terrain change, both offshore and onshore. These changes have to be monitored rigorously. The survey tasks are manifold, and include habitat preservation and protection, for example in areas that are exposed to flooding, land shrinkage or coastal erosion. Surveys are also used for infrastructure maintenance and to ensure coastal navigation safety. As a non-intrusive surveying method, ALB supports all of these tasks without impacting the environment and without putting surveyors at risk.