Anthropologist Rich Wills, recovery leader of a Defense POW/MIA Accountability Agency (DPAA) underwater recovery team, sifts through seashells and rocks on a barge in the Gulf of Tonkin off the coast of Northern Vietnam, May 24, 2015. Wills and the underwater recovery team are searching for two aviators who are believed to have crashed in the area during the Vietnam War. Divers from Mobile Diving and Salvage Unit ONE dredge the ocean floor, and members of the joint recovery team sift through the dredged material in search of identifying evidence. (U.S. Navy photo by Mass Communication Specialist 1st Class Brett Cote/RELEASED)