The first of Portugal’s new air-independent propulsion-capable submarines was handed over to a Portuguese naval crew this past June in Kiel, Germany. The submarine, named the Tridente and numbered S 160, arrived at her new home, the naval base in Lisbon, on 2 August. The Tridente is one of two Type 209PN boats built for Portugal at Germany’s Howaldtswerke-Deutsche Werft shipyard. A second unit of the class, expected to be commissioned in 2011, has been named the Arpão and numbered S 161. The Arpão is currently undergoing sea trials off the coast of Norway. The two Type 209PN submarines were ordered in 2004 and cost a total of roughly 800 million euros. These new units replace the aging French Daphné -class submarines that entered the Portuguese naval service in the late 1960s, the last of which, the Barracuda , is set to retire by the end of 2010.