U.S. Marines with the Maritime Raid Force, 31st Marine Expeditionary Unit, 3rd Marine Expeditionary Brigade, provide security as a U.S. Marine Corps CH-53E Super Stallion helicopter lands during a mock raid conducted with Royal Thai Marines in Hat Yao, Kingdom of Thailand, in support of Exercise Cobra Gold 2011 on Feb. 16, 2011. For three decades Thailand has hosted Cobra Gold, one of the largest land-based, joint, combined military training exercises in the world.