The German merchant steam ship SS Libau, also known as SS Castro and masquerading under the cover name of SS Aud, sets sail from the Baltic port of Lübeck on April 9, 1916, loaded with guns and ammunition for the Irish Republican Brotherhood (IRB) as part of the preparation for the Easter Rising.
Masquerading as SS Aud, an existing Norwegian vessel of similar appearance, SS Libau sets sail from the port of Lübeck, under the command of Karl Spindler, bound for the southwest coast of Ireland. Under Spindler is a crew of 22 men, all of whom are volunteers. SS Libau, laden with an estimated twenty thousand rifles, one million rounds of ammunition, ten machine guns, and explosives under a camouflage of a timber cargo, evade patrols of both the British 10th Cruiser Squadron and local Auxiliary patrols.
After surviving violent storms off Rockall, SS Libau arrives in Tralee Bay on April 20. There they are due to meet Roger Casement and others, with Casement having been landed nearby by the German submarine U-19. The SS Libau has no communications equipment aboard, giving them no means of contacting the Irish while en route. As a result, they are unaware that the date for its arrival off Fenit has been altered from Thursday, April 20 to Sunday, April 23.
One of the two cars carrying Volunteers who are supposed to meet SS Libau crash into the River Laune, many miles away, at Ballykissane pier, Killorglin, resulting in the death of three of the four occupants of the car. This leads to no hope of an organised transfer of arms and the gun-running plan nears an end.
SS Libau, attempting to escape the area, is trapped by a blockade of British ships. Captain Spindler allows himself to be escorted towards Cork Harbour, in the company of the Acacia-class sloop HMS Bluebell. The German crew then scuttles the ship. Spindler and his crew are interned for the duration of the war. Roger Casement and his companions are captured in an old ringfort or rath between Ardfert and Tralee.
A number of rifles are recovered from SS Libau before the vessel is scuttled. Several examples exist in various museums in Britain and Ireland. Among these are the Cork Public Museum in Fitzgerald’s Park in Cork, a museum in Lurgan County Armagh, the National Museum of Ireland in Dublin, and the Imperial War Museum in London.