On 18th June 2009, the second Class 209PN submarine for the Portuguese Navy was named N.R.P. ARPÃO by godmother Maria de Jesus Simões Barroso Soares at Howaldtswerke-Deutsche Werft, a company of ThyssenKrupp Marine Systems, in Kiel.

The new submarine has a combined diesel-electric and fuel cell propulsion system. Equipped with ultra-modern sensors and an integrated Command and Weapon Control System, it is optimally suited to its future reconnaissance and surveillance tasks.

The contract for the two submarines was signed in 2004 between the Portuguese State and the German Submarine Consortium (GSC). The first submarine was named N.R.P. TRIDENTE in June 2008. It has started seatrials in March 2009.