Australia’s Integrated Marine Observing System (IMOS) has been operating a wide range of observing equipment throughout Australia’s coastal and open oceans since 2006. IMOS is designed to be a fully-integrated, national system, observing at ocean-basin and regional scales, and covering physical, chemical and biological variables. All IMOS data is openly and freely accessible to the marine and climate science community, other stakeholders and users, and international collaborators.