170131-N-DH124-064 PORT HUENEME, Calif. (Jan. 31, 2017) Seabees assigned to Naval Mobile Construction Battalion (NMCB) 4 conduct a buddy check to ensure they have properly donned their chemical, biological and radiological gear during Command Post Exercise (CPX) 3. The intent of CPX-3 is to establish command, control, communication, computer and intelligence infrastructure to prepare for the battalion's upcoming field training exercise. (U.S. Navy photo by Mass Communication Specialist 1st Class Rosalie Chang/Released)