Context: After Russia withdrew its larger warships due to a series of devastating attacks, Ukraine's advancing drone boats seem to be targeting smaller, high-speed vessels in the Black Sea.

Black Sea

• About: A marginal mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. 
• Bordering countries: Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine.
• Main river: The Black Sea is supplied by major rivers, principally the Danube, Dnieper and Dniester.
• Mountains: It is surrounded by the Pontic Mountain in the South, Caucasus Mountain in the East, and Crimean Mountain in the North.
• Island: It contains several islands, with the largest ones being Snake Island (Ukraine), Giresun Island (Turkey), and St. Ivan Island (Bulgaria).
• Connecting water bodies: 

o Drains into the Mediterranean Sea via the Turkish Straits and the Aegean Sea.  

o The Bosporus Strait connects it to the small Sea of Marmara which in turn is connected to the Aegean Sea via the Strait of the Dardanelles.

o To the north, the Black Sea is connected to the Sea of Azov by the Kerch Strait.

• Meromictic Basin: The Black Sea is the world’s largest body of water with a meromictic basin. 

o A meromictic lake has layers of water that do not intermix.