The ocean has a fundamental role regarding climate regulation and global biochemical cycles. Since the Industrial Revolution, said role has suffered major changes that have great impact on its functioning: global warming associated with the increase in the concentration of greenhouse gases in the Earth’s atmosphere has led to significant changes in the circulation of matter and energy in the ocean. In addition, and in the context of global change, sea level is expected to rise between 40 and 80 cm by 2100 (IPCC, AR6, 2021), which will have important social implications, as around 50% of the world’s population lives in the coastal zone. The oceans also function as providers of services and resources of immense importance for human populations’ development. Improving knowledge about the ocean and its functioning is crucial for the future development of humanity. Ocean observation is a fundamental step in this direction, and it has already been integrated into major international environmental research and management programmes.