THROUGHOUT THE MORNING OF WEDNESDAY, MAY 5, heavy fog lingered over the sea off Ireland. From 4:00 A.M. on, every time Schwieger checked on the weather through his periscope all he saw was a dark opacity. He held U-20 on a southerly course and kept its speed slow, probably about 5 knots, to conserve battery power. At 8:25 A.M. Schwieger gauged visibility as good enough to bring the boat to the surface, though banks of fog persisted all around him.
His crew now decoupled the two electric engines and engaged the diesels to bring U-20 to cruising speed and recharge the batteries. Somewhere off to his left, in the murk, was the southwest coast of Ireland, here a phalanx of stone cliffs jutting into the North Atlantic. He would soon pass Valentia Island, where the British had built a powerful wireless transmitter. Schwieger’s own wireless man would by now be picking up strong signals from the Valentia tower, but could not read the codes in which they were sent.
U-20 moved through curtains of fog. By 12:50 P.M. Schwieger believed himself to be abreast of the Fastnet Rock, though he could not see it. The rock was one of Britain’s most prominent maritime landmarks, a road sign to the Western Approaches. Irish immigrants in the nineteenth century knew it as “Ireland’s Teardrop” because it was the last bit of Ireland they saw before their ships entered the North Atlantic en route to America. Here Schwieger ordered a left turn, to begin sailing along Ireland’s south coast toward Liverpool. This was the upper edge of a great funnel of ocean called the Celtic Sea, where inbound ships converged from north, west, and south. It was the perfect hunting ground for a U-boat, but Schwieger saw nothing.
He wrote, “During the whole afternoon no steamer sighted in spite of the clearing weather, although we found ourselves within one of the main shipping lanes.”
Visibility improved. Soon Schwieger was able to see the Irish coast, but only for a few moments. Over the next three hours, U-20 cruised on the surface and encountered no ships of any kind. The evening haze began to gather once again.
Just before five o’clock, while off the coast of County Cork, Schwieger spotted what at first seemed to be a large square-rigged sailing ship. In the haze, it cut a lovely figure, its three masts billowing with canvas. Unlike other U-boat commanders, who sank such ships with reluctance, Schwieger was unmoved. He saw a target. U-20 turned toward the ship, and Schwieger’s men loaded and aimed its deck gun.
As Schwieger got closer, he saw that once again the light and haze had deceived him. The ship did have three masts, but it was only a small schooner. He signaled the vessel to stop. Although he had fired on ships many times without warning, here he returned, briefly, to cruiser rules. “As no danger existed for our boat in approaching,” he wrote, “we made for the stern of the sailer.”
He ordered the schooner’s captain and four-man crew to abandon ship and bring its registry and cargo manifest over to U-20. The schooner proved to be the Earl of Lathom, out of Liverpool, carrying rocks from Limerick. It weighed all of 99 tons.
As the schooner’s crew began rowing away, Schwieger ordered his men at the gun to begin firing at the schooner’s waterline. Despite its small size and decidedly nonbuoyant cargo, the vessel proved a stubborn target. Shot after shot boomed across the sea and exploded against its hull. Schwieger’s gun crew needed twelve shells to sink it.
SEVERAL HOURS later, as dusk and fog gathered, Schwieger found another target. A steamship emerged from the fog, very near—too close to allow Schwieger to prepare an attack. He turned U-20 away, to gain sea room, but kept the boat on the surface. The steamship stopped, apparently expecting an examination under cruiser rules.
Outwardly, the vessel weighed about 3,000 tons and seemed to be Norwegian, but Schwieger and his pilot, Lanz, sensed something amiss. The markings were unusually high on the hull, and Schwieger suspected they might have been painted onto tarpaulins.
Schwieger maneuvered for a torpedo attack. He ordered a bronze torpedo, set to run at a depth of 8 feet. When U-20 was about 330 yards away from the steamer, Schwieger gave the order to fire.
He missed.
The bubbles rising to the surface from the torpedo’s compressed-air engine revealed its path. As the torpedo track moved toward the target, the ship began a sudden acceleration and veered away. As best Schwieger could tell, the torpedo went past or under the stern.
Now it was Schwieger’s turn to flee. He feared the ship might be armed. “After the shot I turned around hard and ran away in order to avoid the danger of being fired upon,” he wrote. “For this reason I did not consider a second attack. Steamer disappeared quickly in the fog.”
In his log entry at 8:10 that night, he contemplated what had occurred. The torpedo had seemed to lose speed as it approached the target, he wrote. “I had considered a miss out of the question, even after the torpedo had been fired, considering our favorable position and the fact that [the] steamer could not make much headway.” Remarkably the ship had then managed to accelerate from a dead stop to make its escape.
Over the next hour the dense fog returned and once again forced Schwieger to submerge. This was the end of his sixth day at sea, and all he had sunk was a 99-ton sailboat.