Coastal seas lie at the interface between the open ocean, land and society, yet observing, modelling and forecasting across these scales remains challenging. In a changing climate, improving coastal monitoring capabilities and developing innovative coastal products is vital to protect and manage coastal areas. Novel coastal observations (including satellite,land-based remote sensing and in situ data), advanced hydrological and coastal models, land-ocean data integration, coupling modelling and data assimilation all serve to improve coastal monitoring, and forecasting. Novel numerical model approaches and Artificial Intelligence (AI), including hybrid physics-AI methods, are further enabling pan-European transferable approaches. This session focuses on advanced, seamless ocean observing and forecasting, from global/regional systems to high-resolution coastal systems, through new and improved observations, models, methods, and co-produced (with national or regional authorities) coastal products and services. We particularly welcome contributions that bridge European and regional ocean products with coastal systems and demonstrate interoperable workflows, uncertainty quantification, integration with operational services, and uptake by end users. These advances aim to provide the marine knowledge needed for coastal applications addressing environmental and social challenges and those enhanced by climate change, such as: pollution and eutrophication hazard/risk mapping, coastal erosion and flooding, resource management, harmful algal blooms, and combating ecosystem degradation and restoration, supporting Marine Protected Areas, and addressing natural hazards and extreme events.