Dead Wake: The Last Crossing of the Lusitania

by Erik Larson

As the boat descended through ever colder waters, the contrast between the warm interior and cold exterior caused condensation, which soaked clothing and bred colonies of mold. Submarine crews called it “U-boat sweat.” It drew oil from the atmosphere and deposited it in coffee and soup, leaving a miniature oil slick. The longer the boat stayed submerged, the worse conditions became. Temperatures within could rise to over 100 degrees Fahrenheit. “You can have no conception of the atmosphere that is evolved by degrees under these circumstances,” wrote one commander, Paul Koenig, “nor of the hellish temperature which brews within the shell of steel.” The men lived for the moment the boat ascended to the surface and the hatch in the conning tower was opened. “The first breath of fresh air, the open conning-tower hatch and the springing into life of the Diesels, after fifteen hours on the bottom, is an experience to be lived through,” said another commander, Martin Niemöller. “Everything comes to life and not a soul thinks of sleep. All hands seek a breath of air and a cigarette under shelter of the bridge screen.” All these discomforts were borne, moreover, against a backdrop of always present danger, with everyone aware they faced the worst kind of death imaginable: slow suffocation in a darkened steel tube at the bottom of the sea. On one of U-20’s patrols, this prospect came to seem all too real. IT WAS EARLY in the war, when U-boat commanders and British defenders alike we...