On one occasion E31 came across a disabled Zeppelin--which earlier in the day had been winged by light cruisers of the Harwich Force--sitting on the water. The Zeppelin showed fight; she was sunk by the submarine's gunfire, and the survivors, seven in number, were taken off as prisoners. During the night, on the homeward voyage, the submarine was overtaken by a German light cruiser, which opened fire on her. "Ach, zey com!" triumphantly exclaimed one of the prisoners, a sulky German officer, who up till then had not uttered a word. The order had been given to dive, but for some reason this could not be effected quickly. Delay was dangerous, so the officer of the watch put the submarine's helm hard over, and she went round in circles, presenting a difficult target. The German cruiser now proceeded to steam round in still larger circles. For a while she was so close to the submarine that she could not get her guns to bear on her. Then she attempted to ram her, but in vain. Eventually the E31 dived, and, just before her stern went under, she was struck in the after casing by a six-inch shell. When she had sunk she released some oil, and the Germans, seeing this, reported her as lost. But she was not much damaged, and got home. This throwing out of oil from a diving submarine was a ruse employed by both sides, and soon the appearance of a volume of oil upon the surface of the sea was no longer accepted as proof of a successful hit. But at any rate it left the other side in doubt as to what had happened.