The Southern Ocean and the Antarctic shelf seas have been undergoing massive changes for several years. They build on the existing efforts of networks such as SCAR (Scientific Committee on Antarctic Research) and SOOS (Southern Ocean Observing System). The project aims to establish an internationally coordinated and synchronised observing system in the Southern Ocean and the coastal regions of Antarctica. “SYNCHRONY will expand and improve Antarctic observing networks, consolidate existing datasets, collect new ones and make them more accessible to the international research community. It will mark a milestone towards a comprehensive polar observing system.