Battle off Ulsan The naval Battle off Ulsan ( Japanese : 蔚山沖海戦 " Urusan ' oki kaisen " ; Russian : Бой в Корейском проливе , " Boi v Koreiskom prolive " ) , also known as the Battle of the Japanese Sea or Battle of the Korean Strait , took place on 14 August 1904 during the Russo - Japanese War , four days after the Battle of the Yellow Sea . Background . The Vladivostok Cruiser Unit of the Russian fleet made up of the armoured cruiser s " Rossia " , " Gromoboi " and " Rurik " raided Japanese sea commerce in the first stage of the war . A telegram from the First Pacific Squadron at Port Arthur reached Vladivostok on the afternoon of 11 August 1904 . But the Vladivostok cruisers were not ready for action , since as late as 5 August 1904 , a telegram had been received from Admiral Wilgelm Vitgeft stating that he had decided to perish with Port Arthur . Owing to the delay in sailing , there was little hope of being able to assist the First Pacific Squadron at the critical passage of the Tsushima Straits . However , the Russian command assumed that Admiral Vitgeft would be successful in breaking through the Japanese blockade , and therefore ordered Rear Admiral Jessen to sortie the Vladivostok Cruiser Squadron to rendezvous with the fleet in the Sea of Japan . Sortie . The warships of the Imperial Russian Navy ( IRN ) formed in a line abreast at intervals of four nautical miles ( 7 km ) and headed southward at , in hourly expectation of sighting the Port Arthur Squadron . However , the fleet had not been sighted by the following morning . As the Russian squadron approached Busan , Admiral Jessen advised his captains that he had no intention of attempting to pass Tsushima Straits , and ordered the squadron back to Vladivostok . It was a fateful decision . The Imperial Japanese Navy ( IJN ) was made up of more modern armored cruiser s ; the " Izumo " , " Azuma " , " Tokiwa " , " Iwate " , and two protected cruiser s " Naniwa " and " Takachiho " which were under the command of Vice Admiral Hikonojo Kamimura who had just recently passed very close to the Russian squadron in the dark on opposite courses but neither was aware of the other . Ever since 01 : 30 of 14 August 1904 , Vice Admiral Kamimura had been heading back from his night patrol area on a course that took him directly to the Russian squadron . When Admiral Yessen started to turn back to Vladivostock , he sighted the four IJN armored cruisers . The situation was ideal for the Japanese . It was dawn on a fine summer day , and the enemy was as far from Vladivostok as it was possible to be in the Sea of Japan , with the IJN between themselves and their distant base . The battle . At 0520 on 14 August 1904 the fleets had closed to 7800 m , and the IJN opened fire first . For some reason , Kamimura , in assigning targets , concentrated fire on the " Rurik " , the last and weakest in the IRNs column . Subjected to twice the bombardment administered to her stronger comrades . " Rurik " lost most of her officers in a short time , and although extremely damaged , remained afloat , the diminishing number of survivors continuing to fire the few remaining guns until the very last , in a gallant display of classic heroism that won the admiration of the IJN . On the easterly run the Japanese ships took some hits , but nothing comparable to what they inflicted . It would be assumed that when the Russians sheered away , Admiral Kamimura would have pressed his advantage closer . Inexplicably , this did not happen . Kamimura oddly held his course during the IRN turn , and when the IJN turned a few minutes later , it was to a new tack that actually lengthened rather than narrowed the range . The remaining IRN cruisers tried to cover the " Rurik " , but with increasing damage , Admiral Jessen decided at 08 : 30 to scuttle the " Rurik " , and save his other ships by heading back towards Vladivostok . IJN cruisers chased them for some time , and firing continued , with more damage to the Russian cruisers and slight damage to the " Iwate " and the " Azuma " . The Russians were in a far worse condition than the Japanese , but Admiral Kamimura then made another inexplicable decision : after pursuit of only three hours , while still on the high seas , and with long daylight steaming hours between the IRN cruisers and Vladivostok , at 11 : 15 hours the IJN ceased the chase , and turned back towards Busan . Despite Kamimura ' s failure to destroy the two remaining Russian cruisers , he was hailed as a hero in Japan , and the Vladivostok Cruiser Squadron never threatened Japanese shipping again . Russian point of view . From the Imperial Russian Navy ' s point of view , the " Rurik " was scuttled by her own crew , not by Admiral Jessen ' s decision . The " Rurik " was hit by a shell in her unarmoured stern and the steering mechanism was destroyed , immobilizing her rudder in an elevated position . So the maximum speed of " Rurik " had been greatly reduced and her steering had to be performed by reducing the revolutions of each one of her propellers . Admiral Jessen successfully diverted all four IJN armoured cruisers and hoped that " Rurik " could withstand against the " Naniwa " and " Takachiho " . However , the condition of " Rurik " was rather bad . First Rank Captain Trusov , her commander , and all senior officers were killed . Finally , Lieutenant Ivanov ( the thirteenth in command ) ordered the " Rurik " to be scuttled . The " Russia " and " Gromoboi " successfully repelled the attack of Kamimura ' s cruisers at the price of sustaining heavy damage , but IRN sailors , while still under fire , were able to repair the main 203 mm ( 8 inch ) guns and continue to engage with them . Faced with an increasing rate of fire from the Russian cruisers and with his ammunition supplies nearly depleted , Admiral Kamimura decided to stop pursuit . The very heavy Russian casualties suffered in the battle were the result of two factors : the bursting charges in Japanese shells was picric acid ( trinitrophenol ) which on detonation turned the shells into very large numbers of fragments . Additionally the Russian ships lacked protective gun shields for the crews . Order of battle . Russia . Vladivostok cruiser force - Rear Admiral Karl Jessen : Japan . 2nd Squadron - Vice Admiral Hikonojo Kamimura