It is connected with the Aegean Sea by the Bosporus, the Sea of Marmara, and the Dardanelles. Romania, Bulgaria, and the European portion of Turkey bound it on the west. The Crimean Peninsula projects into the Black Sea from the north, forming the shallow Sea of Azov on the east and the Karkinitskiy Gulf on the west. The former is almost entirely cut off from the Black Sea. The sea receives the drainage of a large part of central and eastern Europe through the Dnepr, Dnestr, Southern Bug, and Danube rivers.
Severe storms occur frequently on the sea, particularly during the winter season.
The prevailing winter winds are from the north. The Black Sea is abundantly stocked with valuable sturgeon and other fish. As an outlet for the products of Ukraine and adjoining republics, it is of special importance in regional commerce. Navigation in the Black Sea began early. Many of the colonial and commercial activities of ancient Greece and Rome, and in later times of the Byzantine Empire, centered on it.