潜艇(submarine)
能在水下持续运行的海军战舰。18～19世纪美国的布什内尔（D. Bushnell, 1742年～1824）和富尔敦等发明家开始作有关潜水艇的实验。1898年霍兰（J. P. Holland, 1840～1914）的「荷兰号」下水，该潜艇同时具备内燃机（水上航行时使用）和电动机（水下航行时使用）。美国政府於1900年购买了它。莱克（S. Lake, 1866～1945）改良革新的潜水艇最先在欧洲获得采用，後来美国也采用。到第一次世界大战前夕，世界所有的主要海军都采用这种潜水艇。德国的U－艇尤其是具有潜在的威胁武器。第二次世界大战中，潜水艇战在世界各大海域中都很常见。1940年德国人采用的柴油引擎通气管为水下的柴油引擎提供新鲜空气，并因此使其不用浮上水面更换电池。美国军舰「鹦鹉螺号」在1954年开始使用核潜艇。由铀燃料核反应器提供的强大能源使潜艇可以在水下运行很长的时间。声纳在导航和侦探敌舰时发挥重要作用。潜艇可以配备带有核头的航行导弹和弹道导弹。由於潜艇的位置难以确定，在核武国家占有很重要的地位。亦请参阅depth charge、Trident missile。
English version：
submarine
Naval vessel capable of operating under water for sustained periods. In the 18th-19th century, American inventors such as David Bushnell (1742?-1824) and Robert Fulton experimented with submarines. In 1898 John P. Holland (1840-1914) launched the Holland, which had both internal-combustion engines (for surface locomotion) and electric motors (for submerged cruising); it was purchased by the U.S. government in 1900. The innovations of Simon Lake (1866-1945) were adopted first in Europe and later in the U.S. By the eve of World War I, all major navies had submarines; the German U-boat was an especially potent threat. World War II saw extensive submarine campaigns in all the world's oceans. The snorkel, adopted by the Germans in 1940, supplied fresh air to the diesel engine of the submerged craft, thus making it unnecessary to surface to recharge batteries. The shift to nuclear submarines began with the launching of the USS Nautilus in 1954. The abundant power provided by the uranium-fueled reactor meant that submarines could remain submerged and operate at high speed indefinitely. Sonar is widely used in navigation and to detect enemy vessels. Subs may be armed with cruise missiles and ballistic missiles fitted with nuclear warheads. Because they are so difficult to locate, they have been of great importance in the forces of nuclear-armed nations. See also depth charge, Trident missile.