U 21

U 21 or U21 stands for:

• An age class in sports, see classification in sports
• U- 21 team
• Subway Line 21 (Nuremberg ) ( part running the metro line 2)

U 21 is the name of U- boats:

• SM U 21 (1913-1919), a submarine of the German Imperial Navy
• U 21 ( kuk Marine) ( 1916-1919 ), a submarine of the Austro-Hungarian Navy
• U-21 ( Kriegsmarine ) ( 1936-1944 ), a submarine of the German Navy
• U 21 (Bundeswehr) ( 1974-1998 ), a submarine of the German Navy

See also:

• Submarine class XXI ( Type 21 )

• Disambiguation
• Abbreviation