Marines assigned to Battery Q, 5th Battalion, 11th Marine Regiment, 1st Marine Division provide security during the 5/11 Command Post Exercise aboard Marine Corps Base Camp Pendleton, Calif., Nov. 18, 2015. The CPX provided an opportunity for the Marines to refresh their skillsets in preparation for exercise Steel Knight 2016. - Marines assigned to Battery Q, 5th Battalion, 11th Marine Regiment, 1st Marine Division provide security during the 5/11 Command Post Exercise aboard Marine Corps Base Camp Pendleton, Calif., Nov. 18, 2015. The CPX provided an opportunity for the Marines to refresh their skillsets in preparation for exercise Steel Knight 2016.