Equipment Operator 3rd Class Marbien Tangonan, of Naval Mobile Construction Battalion (NMCB) 4, uses a Caterpillar 120M grader to level the ground after a filled in excavation site during an airfield damage repair exercise held on board Naval Base Ventura County, Port Hueneme, Calif. Completing the exercise brings NMCB 4 one certification closer to full mission readiness. (U.S. Navy photo by Mass Communication Specialist 1st Class Charles Panter/Released)