171116-N-GZ832-0021 OKINAWA, Japan (Nov. 16, 2017) Seabees assigned to Naval Mobile Construction Battalion (NMCB) 4 headquarters company, prepare for a Command Post Exercise (CPX) by setting up Base-X shelters for the command operation center. The intent of the 2 day exercise is to establish command, control and communications and train and evaluate personnel in a real world environment. (U.S. Navy photo by Mass Communications Specialist 2nd Class Benjamin Stevens/Released)