An experience of another kind is described in a number of the _Illustrierte Zeitung_ of July 12, 1917. The date of the engagement was February 22, in the same year.
‘Just at dinner time the watch reports a tank steamer in an E.N.E. direction, steering a course approximately towards the boat. Masts, bridge and funnel are visible above the horizon. Tank steamers are very hard to sink, as they have stray bulkheads fitted to keep their volatile cargo in check. The torpedo must hit the aftermost engine to stop the tank steamer. The periscope must only be shown occasionally for a very short time, so as not to alarm her. The torpedo is fired at 700 metres (765 yards) away, the submarine comes to the surface and fires a shot from her forward gun, as a signal to stop. The steamer understands, lowers two boats, and the crew abandon ship. Steam is blown off in a high white column. The master appears to be a sensible man, who does not intend to expose himself to shell fire for no purpose. The submarine approaches submerged and takes stock of the vessel--a black tank steamer, grey superstructure, no guns--the naval patent log hanging over the stern. The submarine then makes for the boats. As soon as they see her periscope, they hastily pull away. At length the submarine finds a favourable position to come to the surface, outside the boats, so that the latter are in the line of fire. She rises to the surface, with compressed air in her midship diving-tanks, the conning-tower hatch is opened and the process of blowing out the tanks begins. The boats have pulled away a little further, and just as they are being hailed there is a flash from the steamer.
‘A submarine trap! Alarm. Flood tanks, dive rapidly! The seconds seem interminable. The superstructure abaft the conning-tower is penetrated, and hardly has the hatch been closed when there is a sharp report in the conning-tower, a yellow flash, and explosive gases fill the air. A shell has penetrated the side of the conning-tower and exploded inside. All the fittings are shattered by splinters; there is a sound of breaking glass. Another shell will fall directly and that will be the end of the war for us. Water is splashing in through the shot hole; the boat is sinking into the shelter of the deep. The conning-tower is cleared, the inner hatch and voice-pipe cock are closed, and the leads laid into the control room.