Marine Corps Lance Cpl. Corey Arensen maneuvers through a mud pit during the endurance course at the Jungle Warfare Training Center in Okinawa, Japan, Jan. 15, 2018. Arensen is a machine gunner with India Company, 3rd Battalion, 3rd Marine Regiment Recruit MCMAP Training By Sarah Sicard on February 20, 2017 T&P on Facebook Looking for a great career? Or know another veteran, service member, or military spouse who is? Get started at Hirepurpose.