Petty Officer 1st Class Steven Maldonado and Gunnery Sgt. Javier Vega conduct a perimeter security check. Petty Officer 1st Class Steven Maldonado and Gunnery Sgt. Javier Vega, both assigned to Naval Mobile Construction Battalion 40, conduct a perimeter security check around a new combat outpost in Diwar, Afghanistan, on Dec. 18, 2010. Active duty and reserve component Seabees assigned to Naval Mobile Construction Battalions 40 and 18 secure and fortify a combat outpost in Diwar, Afghanistan. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 118689-R-BFK56-218.jpg Photo Gallery