that "to oppose imperialist aggression, we must build a powerful navy". During the Landing Operation on Hainan Island, the communists used wooden junks fitted with mountain guns as both transport and warships against the ROCN. The navy was established on 23 April 1949 by consolidating regional naval forces under Joint Staff Department command in Jiangyan (now in Taizhou, Jiangsu). The Naval Academy was set up at Dalian on 22 November 1949, mostly with Soviet instructors. It then consisted of a motley collection of ships and boats acquired from the Kuomintang forces. The Naval Air Force was added two years later. By 1954 an estimated 2,500 Soviet naval advisers were in China—possibly one adviser to every thirty Chinese naval personnel—and the Soviet Union began providing modern ships. With Soviet assistance, the navy reorganized in 1954 and 1955 into the North Sea Fleet, East Sea Fleet, and South Sea Fleet, and a corps of admirals and other naval officers was established from the ranks of the ground forces. In shipbuilding the Soviets first assisted the Chinese, then the Chinese copied Soviet designs without assistance, and finally the Chinese produced vessels of their own design. Eventually Soviet assistance progressed to the point that a joint Sino-Soviet Pacific Ocean fleet was under discussion. 1950s and 1960s Through the upheavals of the late 1950s and 1960s the Navy remained relatively undisturbed. Under the leadership of Minister of National Defense Lin Biao, large investments were made in naval construction during the frugal years immediately after the Great Leap Forward. During the Cultural Revolution, a number of top naval commissars and commanders were purged. Naval forces were used to suppress a revolt in Wuhan in July 1967, but the service largely avoided the turmoil affecting the country. Although it paid lip service to Mao and assigned political commissars aboard ships, the Navy continued to train, build, and maintain the fleets as well the coastal defense and aviation arms, as well as in the performance of its mission. 1970s and 1980s In the 1970s, when approximately 20 percent of the defense budget was allocated to naval forces, the Navy grew dramatically. The conventional submarine force increased from 35 to 100 boats, the number of missile-carrying ships grew from 20 to 200, and the production of larger surface ships, including support ships for oceangoing operations, increased. The Navy also began development of nuclear attack submarines (SSN) and nuclear-powered ballistic