Trench Training U.S. Navy Ensign Frank S. Sysko holds his breath while exiting a mud-filled trench during jungle warfare training evolution hosted by Marines with the Jungle Warfare Training Center in Okinawa, Japan, Jan. 12, 2016. Sysko is assigned to Naval Mobile Construction Battalion 3, which is deployed to several countries in the Pacific to perform construction operations and humanitarian assistance projects. U.S. Navy photo by Petty Officer 1st Class Michael Gomez SHARE: Download: Full Size (0.53 MB) Credit: MC1(SW) Michael Gomez VIRIN: 160112-N-TE668-115.JPG Photo Gallery