"Q versus U"

	The Allies primary weapon against U-boats is the Q-ship.  Q-ships are armed ships disguised as a merchant or fishing ship.  Q-ships make it difficult for the Germans to freely attack any ship for fear it might be a Q-ship.  




http://www.inquisitor.freeuk.com/nis/qs/index.html
http://www.naval-history.net/WW1_Navy-British-Q-ships.htm