CHONOS is a web platform available at http://chonos.ifop.cl/ . It is composed of a variety of products based on numerical oceanographic modelling of Chilean Patagonia. CHONOS emerged as a response to numerous uncertainties in oceanographic knowledge of the southern and inner seas of Chilean Patagonia, a region where diverse economic, sociocultural and environmental conservation interests overlap, requiring a source of quality information that at the time was not freely or operationally available. The products of CHONOS are designed to provide relevant information for environmentally sustainable decision-making of anthropic activities where information gaps are jointly identified by national authorities, and the scientific and local communities.