Airborne geophysical methods have great potential in delineating subsurface information down to, e.g., 200 m depth. This information is essential for planning purposes for manifold geoscientific, economic or environmental questions, like, e.g., utilization and protection of fresh groundwater resources, land utilization or industrial planning. These data integrated into a three-dimensional geographical information system provide a perfect tool for spatial planning. Beside geological or geophysical basic information also changes of surface and subsurface data in time and space may be documented by repeated surveys. Building on previous results and knowledge a general airborne survey of the German North Sea coastal area is projected and started in 2008. Emphasis is placed on the mapping of fresh-water-saltwater interfaces, saltwater intrusions and the evaluation of the coastal aquifers as well as on the mapping of submarine freshwater discharges. With the mapping a basis for monitoring should be set up.