helicopters, transports, and utility/training aircraft was retained. Navy The "navy" of Somoza's National Guard consisted of a few old patrol boats. The Sandinistas acquired more modern vessels, although none was larger than fifty tons. The navy's mission was to discourage seaborne Contra attacks and to deter CIA-run operations such as the destruction of diesel storage facilities at Corinto in 1983 and the mining of Nicaraguan harbors in 1984. The Sandinista navy (Marina de Guerra Sandinista—MGS), which had reached a peak strength of 3,000 personnel in 1990, suffered a sweeping reduction to 800 by 1993. The commander of the navy is an SPA officer with the rank of major. The principal bases of the MGS are at the ports of Corinto on the Pacific and Puerto Cabezas on the Caribbean. Other installations are at El Bluff near Bluefields and San Juan del Sur on the Pacific. The Sandinistas had acquired eight Soviet minesweeping boats, of which seven remained in 1993, but none is known to be in operating condition. Three Soviet Zhuk-class patrol boats are believed to be seaworthy, out of seven that remained at the end of 1990. Also believed to be operational are three North Korean fast patrol boats as well as two Vedette-type boats built in France and armed with Soviet 14.2mm machine guns. Sandinista People's Militia The Nicaraguan government established the Sandinista People's Militia (Milicia Popular Sandinista—MPS) to augment the regular troops. The militia represented both a massive political mobilization and the primary means of defending the countryside against the Contras. Individual militias received weekend training in basic infantry weapons and were assigned as guards in sensitive installations or as neighborhood night watches. A typical militia battalion of 700 persons consisted of five infantry companies and various support units. The principal weapons of the MPS were older-model rifles and machine guns and mortars. Militia members displaying aptitude during weekend training sessions were selected for several months of full-time training, followed by up to six months of service in the field. During 1982 and 1983, the militia had primary responsibility for border defense and thus sustained heavy casualties, while the regular army was concentrated at permanent bases. After the installation of the draft in 1983 enabled the SPA to widen its operations, the main function of the mobilized militia became the protection of rural communities. The FSLN claimed that 250,000 persons had received some form of military training,