Ocean forecasting has become an operational service rather recently (since the early 2000s), thanks to the advent of satellite altimetry and ARGO floats measurements . Given the importance of local bathymetry and coastlines characteristics significantly influencing the ocean circulation, regional and coastal ocean forecasting has also developed. Significant progress has also been made thanks to optimizations and technological innovations that have revolutionized the field of ocean forecasting from the global to the coastal scale. This has given rise to the definition of several best practices that enhance forecast accuracy and reliability that concern the: 1) choice of downscaling strategy, 2) choice of lateral open boundary conditions; 3) atmospheric forcing and river conditions; 4) assimilation with mesoscale resolving models considering complex geometries; 5) validation of analyses and forecasts as well as specific solutions for long term reanalysis; 6) uncertainty definition using ensemble forecasting; 7) operational oceanographic products for societal benefit.