Britain's Royal Navy made extensive use of Q-ships to combat German submarines. Camouflaged to look like a civilian sailing vessel or decrepit tramp steamer, the Q-ships were decoys that carried concealed heavy guns. The function of the Q-ships was to appear to be an undefended target. If successful, German submarines would be lured to the surface to sink or destroy the ship by using deck guns, enabling the submarine to conserve its limited supply of torpedoes for use against warships. If a German U-boat surfaced, the Q-ship would immediately display the Royal Navy's White Ensign flag in compliance with international law, then deploy its guns against the submarine. In 150 engagements, British Q-ships destroyed 14 U-boats and damaged 60. 27 of the 200 Q-ships the British employed were lost to German attacks.