180821-N-ZI635-449 CAMP SHELBY, Miss. (Aug. 21, 2018) Lt. Cmdr. Matthew Mattivi and Lt. Cmdr. Mark Christensen, executive officer of Naval Mobile Construction Battalion (NMCB) 133, discuss field operations during the battalions' field training exercise (FTX) at Camp Shelby, Miss. FTX provides a robust training environment where Seabee forces plan and execute multiple mission essential tasks including convoy security, force protection, and camp buildup prior to deployment. (U.S. Navy photo by Mass Communication Specialist 2nd Class George M. Bell/Released)