Q-ships, apparently innocuous merchant vessels with heavy but concealed armaments, were used by the British to combat U-boats. Submarines often surfaced to sink small merchant ship with their deck guns in order to conserve their torpedoes for more attractive. One of the Q-ships was HMS Farnborough, captained by Lieutenant-Commander Gordon Campbell, which was armed with five 12 pounders, two 6 pounders, a Maxim machine gun, rifles and depth charges. She had originally been the collier Loderer. Her crew as a Q-ship was 11 officers and 56 men, compared with six officers and 25 men as a collier.
On 22 March Farnborough was off the coast of Kerry when SM U68 (Kapitänleutnant Ludwig Güntzel) fired a torpedo that missed her. The U-boat surfaced and fired a shot across the bows of what appeared to be a collier. The crew apparently abandoned ship, but the gun crews had remained behind.
U68 closed to 800 yards and opened fire. The collier then raised the white ensign and opened fire. U68 was hit but managed to dive. Campbell then took Farnborough over her and dropped a depth charge. The U-boat came out of the water at a perpendicular angle, revealing damage to her bow. Farnborough fired five more shots into her and then dropped two more depth charges as she dived. Oil and wood then came to the surface and U68 was lost was all hands.
The British first ordered depth charges in August 1915 and began to issue them to the fleet in January 1916. This was the first ever sinking of a submarine by depth charges.
Campbell was promoted to Commander and awarded the Distinguished Service Order. Two of the other officers received the Distinguished Service Cross and three men the Distinguished Service Medal.
 Naval Staff Monograph (Historical) 1926 vol. xv, Home Waters part vi, October 1915 to May 1916. p. 101.
 T. Bridgland, Sea Killers in Disguise: The Story of the Q Ships and Decoy Ships in the First World War (London: Leo Cooper, 1999), p. 14.
 Naval Staff vol. Xv. p. 101.
 A. J. Marder, From the Dreadnought to Scapa Flow; the Royal Navy in the Fisher Era, 1904-1919, 5 vols. (London: Oxford University Press, 1961-70). vol. ii, p. 350.
 (Naval Staff vol. Xv. p. 101.