U-boat is the anglicised version of the German word
U-Boot , a shortening of
Unterseeboot, literally "undersea boat". While the German term refers to any
submarine, the English one (in common with several other languages) refers specifically to
military submarines operated by Germany, particularly in the
First and
Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role (
commerce raiding), 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, the
British Empire, and the United States to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean.
