The Intergovernmental Oceanographic Commission (IOC) of UNESCO is a community of 149 Member States that work together to observe, understand and manage the shared marine environment that unites us all. The deep ocean may be the last frontier of the planet but, for over half a century, the ocean has also played a leading role in building greater international cooperation. Since it was first formed in 1960 the work of the IOC has evolved from the technological optimism of the space age to the more recent challenges posed by climate change and the increasing demands of a rapidly expanding human population. The cumulative threats posed by warming sea temperatures, ocean acidification and pollution have created an even more urgent need for the critical services provided by the IOC. The ocean provides about half of the oxygen we breathe and it directly supports the livelihoods of about 500 million people, especially in the poorest nations. For many of these nations, ocean-related economic activities such as tourism and artisanal fisheries support up to 30% of national economies. For over 50 years the IOC has worked behind the scenes to enable its Member States to work together to strengthen our scientific understanding of the ocean for the benefit of humanity. However, in recent years, there has been a growing need to highlight the unique intergovernmental value that it provides for Member States, the IOC community, the ocean environment and wider society.