160616-N-LV331-004 MEDITERRANEAN SEA (June 16, 2016) Secretary of the Navy (SECNAV) Ray Mabus, left, observes an underway replenishment with Adm. Giuseppe De Giorgi, chief of the Italian navy, while aboard the guided-missile destroyer USS Mason (DDG 87). This was the U.S. Navy�s first underway replenishment where the fuel was made from alternative sources and transferred from a partner nation�s ship. The Italian navy auxiliary ship ITS Etna (A5326) provided Mason with biofuel, made from waste fat beef and inedible vegetable oil, as part of the Great Green Fleet initiative. (U.S. Navy photo by Mass Communication Specialist 2nd Class Armando Gonzales/Released)