150617-N-NT265-167 YOKOSUKA, Japan – Master-at-Arms 3rd Class Kelsey Carlton, from Clearwater, Fla., assigned to Military Working Dog unit at Fleet Activities Yokosuka, prepares to throw a ball while conducting obstacle course training with military working dog Donci. The canines with the unit are used to apprehend suspects, detect explosives and narcotics while searching buildings, ships and submarines.