The Baltic Sea is a non tidal system with only minor sea level changes. On rare occasions strong winds push the water onto the coast or away from it. On the 27th of December 2020 strong southerly winds of up to 30 kts pushed the water away from the southern Baltic Sea coast. The circumstances allow to detect groundwater seeps especially in front of cliff coasts. Within Baltic TRANSCOAST we are aiming at characterising the importance of diffuse water and nutrient inputs into the sea. While riverine nutrient input into the Baltic Sea is well understood, we know very little about the diffuse groundwater sources.