The German practice was to arm merchantmen with hidden weapons and use them as commerce raiders. An auxiliary cruiser, "Hilfskreuzer" or "Handels-Stör-Kreuzer" (HSK), usually approached her target under a false flag with guns concealed, and sometimes with her appearance altered with fake funnels and masts and often a fake paint scheme. The victim was thus engaged at point-blank range and had no chance to escape. In World War I, the Imperial German Navy initially used fast passenger ships, such as past holders of the Blue Riband for fastest North Atlantic crossings, but they made obvious and easy targets because of their very familiar silhouettes. The Germans, therefore, soon moved on to using captured and refitted Allied vessels, but principally modified transport ships. These were slower, but less recognizable. In both world wars, these ships were vulnerable to attack, and were withdrawn before the war ended. Many were sunk after being caught by regular warships – an unequal battle, since auxiliary cruisers had poor fire control and no armor. There were, however, a few success stories. was a former passenger liner that sank two freighters in 1914 before being caught by . Her sister ship, , had a legendary journey, sinking or capturing a total of 15 ships in 1914 and 1915, before finally running out of supplies and having to put into port in Virginia, where the Americans interned her and eventually converted her into the United States Navy troop transport USS "Von Steuben". The most famous German commerce raider of World War I probably was , a sailing ship under the command of the legendary Count Felix von Luckner. However, both and were each much more successful than "Seeadler".