The goal of the MOCCA project is to progress towards the Euro-Argo objectives in “Monitoring the Oceans” and the European effort under the international Argo programme through: (1) Procurement of 150 T/S Argo floats (Core and Iridium) during 2015-2016; (2) Arrangement for their deployment in 2016-2017, including at-sea monitoring; (3) Collected data processing in real-time and delayed-mode, during the period 2015-2019. MOCCA will focus on 5 target deployment areas: (A) Southern Ocean (ice free), to improve the actual poor density in Argo network; (B) Nordic Seas (ice free): based on actual national plans, there are gaps in the area from target identified in the Euro-Argo Strategy document; (C) Marginal Seas endhancement: Baltic Sea, Black Sea, Mediterranean Sea (Aegean and Levantine Seas); (D) Contribution to the global network. Within MOCCA, the Euro-Argo ERIC will also demonstrate its operational capabilities. The data will be made freely available as a European contribution to the international Argo programme. The Euro-Argo ERIC will organise interfaces with operational users and, in particular, with the Copernicus Marine Service and with the Ocean and climate change research communities. MOCCA shall provide additional coverage in the European regional seas and help to further develop the Euro-Argo ERIC infrastructure. It will demonstrate that Europe can significantly improve its contribution to the international Argo programme (number of floats to be procured and deployed per year, float data processing and quality control, data dissemination). The Euro-Argo ERIC is a long-term endeavour and will be in a position to sustain the European contribution to the Argo international programme at the end of this action.