The importance of drone based investigations increased in geophysics during the last years. A milestone in that regard was the development of semi airborne electromagnetic (SAEM) surveys during the DESMEX project. In principle, grounded transmitters generate the EM signal, while the magnetic field is recorded at a drone, respectively. Although originally used for mineral exploration it is possible to adapt the method for groundwater investigations. The major advantage compared to other geophysical methods working on the local scale is that drone based SAEM deliver 3D models of the subsurface resistivity distribution. The project Blue Transition aims to balance water and land use to minimize climate change effects. Investigations on pilot sites in Denmark, Netherlands, Sweden, Belgium, France and Germany are used to develop transnational solutions for water boards, farmers, authorities and society. In this framework, SAEM measurements were carried out in Minstedt (northern Germany) to investigate a deep salinization that infiltrate into a shallow aquifer. Drone based SAEM measurements were conducted in autumn 2023, including four transmitter with corresponding flight lines, covering an area of approx. 4 km2. The results show the saltwater intrusion as an anomaly with low el. resistivities. Comparisons with downhole chloride monitorings match with the inversion results as well as with information about the freshwater-saltwater boundary from the local water board. Further comparisons with airborne TEM measurements also deliver comparable results compared to SEAM results. In summary, drone- based SAEM is able to deliver 3D el. resistivity models on the local scale for saltwater investigations in a depth range of 20 – 200 m below the surface.