On another patrol, the next month, Droescher became the first U-boat captain to circle all of Britain. He had sailed first into the English Channel, via the Strait of Dover, where he had encountered vigorous antisubmarine patrols. Gauging the strait as too dangerous for his return voyage, he traveled north instead, along the west coasts of England and Ireland and around the northern tip of Scotland, thus further demonstrating the range and endurance of U-boats. Germany kept the feat a secret.
Schwieger became captain of U-20 in December 1914, and within a short time the boat gained further notoriety, now for ruthlessness. On January 30, 1915, while patrolling off the coast of France, Schwieger sank three merchant steamers without warning. During that same cruise, he took his boat into the estuary of the Seine itself, though bad weather and fog forced him to remain submerged for 111 of 137 hours. On February 1, he fired a torpedo at a large ship painted white and marked with large red crosses, the hospital ship Asturias. He missed. But the attempt was considered a new low in German callousness. Even his superiors seemed surprised.
Yet among his peers and crew Schwieger was known for his kindness and good humor and for maintaining a cheerful atmosphere aboard his submarine. “She was a jolly boat, the U-20, and a kindly boat,” said Rudolph Zentner, one of U-20’s junior officers, in an interview with Lowell Thomas, for his 1928 book, Raiders of the Deep. Zentner attributed this wholly to Schwieger. “If you want a good and pleasant boat, you must have a good and pleasant skipper.” Schwieger was the son of a long-established Berlin family, well educated, poised, urbane. “He was the soul of kindness toward the officers and men under him,” Zentner said. “His temperament was joyous and his talk full of gaiety and pointed wit.”