The Black Sea is an enclosed sea surrounded by six coastal countries, two of which (Romania and Bulgaria) are EU Member States. The Convention for the Protection of the Black Sea against Pollution, also known as the Bucharest Convention, was ratified at 1994 by all coastal countries. The Bucharest Convention is the only European regional sea convention to which the EU is not a Party. While Romania and Bulgaria are in favor of the EU accession to the Convention, Turkey, Russia and the Ukraine have thus far blocked this accession. In this paper, we develop a compliance game to analyze different positions of the coastal countries relative to the EU's accession to the Convention. Our model also helps defining the proposal that the EU could make to the three opposing states such that they accept the EU as a Party to the Convention. In the context of the EU being a Party, we also investigate whether Romania and Bulgaria may be better off delegating their power of decision to the EU, rather than keeping their individual voting rights.