the reactionary serfdom system had an adverse effect on the development of the Russian Navy. It was especially typical of the Baltic Fleet, which was known for its harsh military drill. Thanks to admirals Mikhail Lazarev, Pavel Nakhimov, Vladimir Kornilov, and Vladimir Istomin, the sailors of the Black Sea Fleet were taught the art of warfare and upholding of military traditions of the Russian Navy, formed in the times of Admiral Ushakov. The Battle of Sinop in 1853 the Black Sea Fleet under Nakhimov made a number of tactical innovations. During the Siege of Sevastopol in 1854–1855, the Russian sailors used all means possible to defend their base from land and sea. In accordance with the Treaty of Paris, Russia lost the right to have a military fleet in the Black Sea. In the 1860s, the Russian fleet which had relied upon sails lost its significance and was gradually replaced by steam. After the Crimean War, Russia commenced construction of steam-powered ironclads, monitors, and floating batteries. These vessels had strong artillery and thick armor, but lacked seaworthiness, speed and long-distance abilities. In 1861, they built the first steel-armored gunboat Opyt (Опыт). In 1869, the Russians began the construction of one of the first seafaring ironclads, (Пётр Великий). Russo-Japanese War On the night of 8 February 1904, the Japanese naval fleet under Admiral Heihachiro Togo opened the war with a surprise attack by torpedo boat destroyers on the Russian ships at Port Arthur, badly damaging two Russian battleships. The attacks developed into the Battle of Port Arthur the next morning. A series of indecisive naval engagements followed, in which the Japanese were unable to attack the Russian fleet successfully under shore batteries (coastal guns) of the harbor and the Russians declined to leave the harbor for the open seas, especially after the death of Admiral Stepan Osipovich Makarov on 13 April 1904. After the attack on Port Arthur, the Japanese attempted to deny the Russians use of the port. On the night of 13/14 February, the Japanese attempted to block the entrance to Port Arthur by sinking several cement-filled steamers in the deep water channel to the port. But the steamers, driven off course by Russian gunfire were unable to sink them in the designated places, rendering them ineffective. Another attempt to block the harbor entrance on the night of 3/4 May with blockships also failed. Mine-laying In March, the energetic