‘At 20 metres (65 feet) there are two sharp explosions, and the boat trembles. The “poor shipwrecked men” have thrown depth-charges after us. A few of the lights go out, and further damage to the main switchboard is averted by timely action. The conning-tower is filling. In theory the boat can still remain afloat, but no one has yet survived to tell us how. The increasing weight causes the boat to sink to 40 metres (131 feet) in spite of her being down by the stern and with the engines at utmost speed. Water spurts through the leaky places, and, owing to short circuits, half the lights and important machinery break down successively--gyro compass, main rudder, forward hydroplane (which, to make matters worse, jams at ‘hard down’), trimming pumps, and all control apparatus. The tricolour captured from the full-rigged ship _La Bayonne_ is pressed into service to plug the leak. The boat must be lightened by compressed air in the after and amidship diving tanks, and brought on to an even keel. She rises, certainly, but is more down by the stern than ever. The after compressed air service breaks down. We must avoid coming to the surface, whatever happens, for up above the enemy is lying in wait to fire at us. At 20 metres (65 feet) the diving-tank valves are opened, and all available men sent forward, in order that their weight may cause the bow to sink. The boat sinks by the bow, and the manœuvre is repeated. In another twenty minutes it becomes impossible to proceed submerged. There is now only one, not very promising, alternative--to come to the surface suddenly and run away, firing as we go. ‘“Compressed air in all the tanks, open galley ventilator, man the guns, Diesel engines ready, and put to utmost speed as soon as possible.”