a separate Coast Artillery Corps (CAC) The CAC was disbanded as a separate branch in 1950. In the first decade of the 20th century, the United States Marine Corps established the Advanced Base Force. The force was used for setting up and defending advanced overseas bases, and its close ties to the Navy allowed it to man coast artillery around these bases. Russo-Japanese War During the Siege of Port Arthur, Japanese forces had captured the vantage point on 203 Meter Hill overlooking Port Arthur harbor. After relocating heavy howitzers with 500 pound (~220 kg) armor-piercing shells to the summit of the Hill, the Japanese bombarded the Russian fleet in the harbor, systematically sinking the Russian ships within range. The Japanese were attacking the city and the Russian ships were trapped in the harbor due to mines, making this one of the few cases of coastal guns being employed in an offensive action. On December 5, 1904, the battleship Poltava was destroyed, followed by the battleship Retvizan on December 7, 1904, the battleships Pobeda and Peresvet and the cruisers Pallada and Bayan on December 9, 1904. The battleship Sevastopol, although hit 5 times by shells, managed to move out of range of the guns. Stung by the fact that the Russian Pacific Fleet had been sunk by the army and not by the Imperial Japanese Navy, and with a direct order from Tokyo that the Sevastopol was not to be allowed to escape, Admiral Togo sent in wave after wave of destroyers in six separate attacks on the sole remaining Russian battleship. After 3 weeks, the Sevastopol was still afloat, having survived 124 torpedoes fired at her while sinking two Japanese destroyers and damaging six other vessels. The Japanese had meanwhile lost the cruiser Takasago to a mine outside the harbor. World War II Norway During the Battle of Drøbak Sound in April 1940, the German navy lost the new heavy cruiser Blücher, one of their most modern ships, to a combination of fire from various coastal artillery emplacements, including two obsolete German-made Krupp 280 mm (11 in) guns and equally obsolete Whitehead torpedoes. The Blücher had entered the narrow waters of the Oslofjord, carrying 1,000 soldiers and leading a German invasion fleet. The first salvo from the Norwegian defenders, fired from Oscarsborg Fortress about 1 mile (1,600 meters) distant, disabled Blücher's main battery and set her afire. Fire from the