I threw on my jacket and hurried for the stern. On my way, on account of the heavy rolling of the boat, I realized what was the trouble. There must be a terrific storm above accompanied by a sea which only the Atlantic could stir up. Lieutenant Petersen confirmed my opinion of the conditions which had developed during the night and added that he had never had so much trouble with the diving rudder before in his life. This meant a great deal, for Petersen was with me when our U-boat had been equipped for service for the first time, and had already gone through all kinds of weather. In spite of all the watchfulness that he and the well-trained crew used, the diving rudder’s pressure was not powerful enough to resist the enormous strength of the waves. The boat was tossed up and down as if she had no rudder whatever. Only after we had submerged twice as deep as we had been were we able to steady the boat to any degree. We could still feel the force of the sea and knew the storm must be terrific. When, at daybreak, we arose to the surface there was no chance to open the hatches. The opal green mountains of waves came rolling and foaming at us. They smothered the boat with the great masses of water, washed completely over the deck and even up over the tower. If any one had dared to open the hatch and go out on the conning tower, he would certainly have been lost. I was standing at the periscope and observed the wrath of the elements. It seemed as if we were in a land of mountains which the U-boat had to climb, only to be suddenly hurled down again. I could see only so far as the next ridge, which always seemed to be even higher than the last, and if there had been any chance of seeing more, it would have been impossible in the flying foam and spray. The rain whipped the water violently and darkened the sky so that it was like dusk. The boat worked itself laboriously through the heavy sea. The joints cracked and trembled when the boat slid down from the peak of a wave to be buried in the deep trough. We had to cling to some oil-soaked object in order not to be tossed about. Through the strain put on the body by the terrible rolling of the boat, by the damp, vaporous air, and by lack of sleep and food, we finally became exhausted, but at this time we had no desire to eat. The storm continued for three days and nights without abating. Then the sky cleared, the wind dropped, and the sea became calmer. At noon of the third day the sun broke through the clouds for the first time. Shortly before this, we had dared open the conning tower hatch and greeted the rays of the sun, although we had to pay for this pleasure with a cold bath.