The revised EU Maritime Security Strategy (EU MSS) Action Plan features a section dedicated entirely to actions with regional focus and four of them are dedicated to the Black Sea. These foresee the following: to promote regional cooperation initiatives (B.3.1); to support the synergies promoted by the Facility for Blue Growth (B.3.2); to support the work done against crime in the Black Sea basin (B.3.3); and to foster multi-stakeholder dialogue in the region (B.3.4).
Following the accession of Bulgaria and Romania to the European Union, the European Commission proposed in April 2007 to the Parliament and the Council in a Communication on the Black Sea Synergy initiative, the EU's key policy framework and its practical contribution to the regional cooperation in the Black Sea. The Black Sea Synergy is part of the broader European Neighbourhood Policy.
The Black Sea is connected with the Mediterranean Sea through the Bosphorus/Istanbul and Daradanelles/Canakkale Straits and with Azov Sea through the Kerch Strait. Of the six states that border the Black Sea, only Turkey is not a party to the UN Convention on the Law of the Sea (UNCLOS), which thus does not apply to it. There are no high seas waters in the Black Sea, and while most instances of overlapping territorial seas, exclusive economic zones (EEZ) and continental shelves have been solved by bilateral delimitation agreements, or settled by the International Court of Justice some overlapping claims remain unresolved. However, they are unlikely to lead to serious disputes due to the limited natural resources in the Black Sea.
Following the 2014 illegal annexation of Crimea and Sevastopol by the Russian Federation, condemned and not recognized by the EU, the regional cooperation in the Black Sea has faced a number of constrains. Notably, the EU is not engaged in any cooperation with Crimean entities that have been taken over by the Russian Federation. Furthermore, developing military build-up in Crimea is creating additional pressures in the region. The recent opening of the Kerch Bridge and further maritime transport restrictions entail further economic consequences for Ukraine.
The Black Sea Synergy remains the EU's policy framework for the region aiming to strengthen regional cooperation, via concrete projects and using the wide range of tools at the EU's disposal. Encouraging a bottom-up approach, identifying and supporting what the partners in the region want to do together are fundamental for the Synergy. The flexible and inclusive design and building confidence are at the core of the initiative. A wide variety of areas, ranging from environment, research and innovation, cross-border cooperation to integrated maritime policy, or civil society support are included in the Synergy. Positive results are further developed, as the ones of the successful EU Cross-Border Cooperation for the Black Sea Basin or the Facility for Blue Growth in the Black Sea.
As for the maritime security aspects, the increased migratory pressure at sea and the continuous Russian military build-up in the Black Sea have marked and shifted the region's security situation. In this context, deepening the maritime situational awareness picture is a key aspect to improving maritime security in the Black Sea.
The countries in the Black Sea region have taken steps to continue to develop practical cooperation of common interest. At operational level in the framework of the Black Sea Coast/Border Guard Cooperation Forum and the Black Sea Border Coordination and Information Centre actions are taken to facilitate the exchange of relevant information between the national centres of the littoral states.
Other initiatives, such as the working group on ‘Development of a common preventive system for early detection of illegal activities in the Black Sea', are operating to improve the monitoring of maritime areas in real time via automatic exchange of information. At the same time, the implementation of other regional security cooperation formats, such as the Black Sea Naval Cooperation Task Group (BLACKSEAFOR) or the Document on Confidence and Security Building Measures (CSBMs) remain hampered by the security situation following the illegal annexation of Crimea.
and the subsequent Communication in 2008 from the Commission to the Council and the European Parliament on the Report on the First Year of Implementation of the Black Sea Synergy https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52008DC039...
and the Joint Staff Working Document, on Black Sea Synergy: review of a regional cooperation initiative in 2015 https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52015SC050...
 This treaty imposes a 15,000tn and 21-day limit to warships belonging to non-Black Sea states entering the Black Sea through the straits.
 EU Cross-Border Cooperation for the Black Sea Basin has a continuous and successful implementation, encouraging economic and social development, pooling resources and competences for environmental protection and conservation, and supporting cultural and educational initiatives.
 The EU Facility for Blue Growth in the Black Sea project aims to improve governance in maritime affairs and facilitate the formulation of common strategic priorities for blue growth in the Black Sea.
 The working group on ‘Development of a common preventive system for early detection of illegal activities in the Black Sea' is developed by the Romanian coast guard.