Petty Officer First Class Jonathon Corey, attached to Naval Mobile Construction Battalion Four, sets up the level on a transit level during an elevation reading, Aug. 19, 2008. NMCB Four, from Port Hueneme, Calif., is on a six-month deployment in support of the Joint Task Force Guantanamo's horizontal and vertical construction projects. Joint Task Force Guantanamo conducts safe and humane care and custody of detained enemy combatants. The JTF conducts interrogation operations to collect strategic intelligence in support of the Global War on Terror and supports law enforcement and war crimes investigations. JTF Guantanamo is committed to the safety and security of American service members and civilians working inside its detention facilities.