171117-N-GZ832-0062 OKINAWA, Japan (Nov. 17, 2017)Seabees assigned to Naval Mobile Construction Battalion (NMCB) 4 work on High Frequency (HF) antenna’s to get them ready for the Command Post Exercise (CPX). 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)