U Boot

U-boat is the anglicized version of the German word , itself an abbreviation of Unterseeboot (undersea boat), and refers to military submarines operated by Germany in World War I and World War II. Although in theory U-boats could have been useful fleet weapons against enemy naval warships, in practice they were most effectively used in an economic-warfare role, enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and the United States to Europe. Austrian submarines of World War I were also known as "U-boats".
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U-boot can refer to:U-boats, military submarines operated by Germany during World War I and World War IIDas U-Boot, a computer software which serves as a bootstrap loader in many embedded systems.Uboot, a Polish beer mix made from beer and vodka
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sub, submarine, ship that travels underwater

nn - submarine (pl. U-Boten)