Since its first edition in 1968, SWIM has become the main international meeting for researchers working on seawater intrusion and coastal groundwater. Over the years, it has provided a forum to exchange new ideas, present recent research, discuss methodological advances, and strengthen collaborations between scientists, practitioners, and water managers.

The theme of SWIM 2025, "Integrating Land and Ocean Approaches in the Study of Coastal Groundwater," emphasized the need for a more integrated understanding of coastal aquifer systems by bringing together the traditionally separate fields of seawater intrusion (SWI) and submarine groundwater discharge (SGD). Reflecting this vision, the conference covered a wide range of topics, including hydrogeology, hydrogeochemistry, geophysics, numerical modelling, groundwater–surface water interactions, ecology, and water resources management.

This volume contains the abstracts of all oral and poster contributions presented during the conference. Together, they provide an overview of current research on coastal groundwater systems, covering new field observations, monitoring techniques, experimental studies, modelling approaches, and management strategies developed by research groups from around the world.

We hope that this collection will be useful not only as a record of the scientific contributions presented at SWIM 2025, but also as a reference for researchers and professionals working on the characterization, understanding, and sustainable management of coastal groundwater.