The Battle of Korsakov, a naval engagement of the Russo-Japanese War, was fought on 20 August 1904 off the southern coast of Sakhalin island. The battle foiled an attempt by the Imperial Russian Navy protected cruiser at escaping Port Arthur to join the Russian cruiser squadron at Vladivostok, Russia, after the Russian Pacific Squadron was scattered in the Battle of the Yellow Sea.
Preliminary moves
Novik was part of the Imperial Russian Navy squadron blockaded in the harbor at Port Arthur, Manchuria, China, by Imperial Japanese Navy forces since the outbreak of the Russo-Japanese War in February 1904. When the Russian squadron finally tried to break out of Port Arthur and reach Vladivostok, Russia, where it could unite with a Russian cruiser squadron based there, it met defeat in the Battle of the Yellow Sea on 10 August 1904. The Russian squadron broke up during the engagement, with some ships returning to Port Arthur and others fleeing southward into the Yellow Sea to seek refuge in Chinese ports. Novik was among the ships that fled south.
On 11 August, Novik encountered the Russian protected cruiser Diana – whose commanding officer intended to steam to Saigon in French Cochinchina – and destroyer Grozovoi in the Yellow Sea, and Novik′s commanding officer informed the other two Russian ships that he intended to take on coal and provisions at Kiaochow in the German Kaochow Bay concession in China and then steam around the east of Japan to Vladivostok. Diana′s commanding officer believed that such a voyage would result in capture by Japanese forces, and he remained intent on steaming to Saigon. Diana and Grozovoi put into port at Shanghai, China, and Novik parted company with them and proceeded alone.
The Japanese had limited information on Novik′s location until 14 August 1904, when they received reports that she had departed Kiaochow at dawn on 12 August and that a neutral merchant ship had sighted a cruiser resembling Novik in the East China Sea halfway between Shanghai and Nagasaki, Japan, at 10:15 on 13 August and that she apparently was bound for Van Diemen Strait (Ōsumi Strait) south of Kyushu. The Japanese initially ordered the protected cruisers Niitaka and Tsushima to proceed to Tsugaru Strait to catch Novik if she attempted to reach Vladivostok via that route, but then cancelled the order after determining that the two cruisers were needed in the Shanghai area to search for the Russian protected cruiser Askold. This decision afforded Novik the opportunity to steam northward to the east of Japan without interference. She passed south of Yakushima in the Ōsumi Islands at 05:30 on 14 August and entered the Pacific Ocean, turning north.
A Japanese merchant ship sighted Novik passing Yakushima early on 14 August, and when word of the sighting reached the Japanese naval command on the morning of 15 August, they finally were able to organize a pursuit. They ordered the protected cruisers Chitose and Tsushima under the overall command of the commanding officer of Chitose to proceed north with all speed to Tsugaru Strait and destroy Novik if she attempted to enter the Sea of Japan from the Pacific Ocean via that strait. Tsushima received the orders promptly, and unable to contact Chitose, proceeded northward through the Sea of Japan on her own. Chitose did not receive the order until around sundown on 15 August, and was unable to follow Tsushima until 03:30 on 16 August.
Tsushima arrived at Hakodate, Japan, on Tsugaru Strait around sunset on 17 August 1904, and Chitose met her there at about 13:00 on 18 August. They received orders to patrol in the Sea of Japan off the western side of Tsugaru Strait until 08:00 on 19 August. If Novik did not appear by that time, they were to split up, with Chitose continuing to watch Tsugaru Strait while Tsushima steamed north to investigate La Perouse Strait. When there was no sign of Novik, they duly parted company as ordered.
About an hour after Tsushima headed north, word arrived that Novik had passed through Friza Strait between Uruppu and Etorofu in the Kurile Islands and entered the Sea of Okhotsk. The Japanese surmised that Novik intended to pass through La Perouse Strait on her way to Vladivostok and would have to coal at Korsakov on the south coast of Sakhalin Island, and they ordered Chitose to join Tsushima in La Perouse Strait. Tsushima began searching the strait around 08:00 on 20 August 1904, and Chitose joined her at around 10:00. With no sign of Novik, the commanding officer of Chitose ordered Tsushima to steam into Aniva Bay and see if Novik was at Korsakov.