PACIFIC OCEAN – (Oct. 6, 2016) USS NIMITZ (CVN 68). A MK-38 25mm machine gun system fires rounds during a training exercise on the fantail of USS Nimitz (CVN 68). Nimitz is underway conducting sea trials as part of the completion of a 20-month extended planned incremental availability. Once Nimitz completes sea trials, the ship will begin a training and qualification cycle in preparation for an upcoming 2017 deployment. (U.S. Navy photo by Petty Officer 3rd Samuel Bacon/Released)