Marines with 8th Engineers Support Battalion along with Combat Logistics Battalions 2 and 6 hold a concrete hose while Lance Cpl. Joseph Cavalier pours concrete into cinder block walls aboard Marine Corps Base Stone Bay, N.C., Aug. 15, 2014. The units built these walls over the course of two weeks for the MARSOC Master Breachers Course, were critical skills operators will get hands on experience on how to breach different types of walls. (U.S. Marine Corps Photo by Cpl. Andy J. Orozco/Released)