150420-N-RB579-001 DAKAR, Senegal (April 20, 2015) Master-at-Arms 3rd Class Joshua Putman, from Dallas, stands a security watch aboard the Military Sealift Command's joint high-speed vessel USNS Spearhead (JHSV 1), while moored in Dakar, Senegal, April 20, 2015, in support of Exercise Saharan Express 2015.. Saharan Express is a U.S. Africa Command-sponsored multinational maritime exercise designed to increase maritime safety and security of the west coast of Africa. (U.S. Navy photo by Mass Communication Specialist 1st Class Joshua Davies/Released)