U.S. Marine Corps Sgt. Daniel Holtz, a combatant diver with 3d Force Reconnaissance Company, 4th Marine Division, Marine Forces Reserve, exhales through his SCUBA second stage regulator during dive training in Mobile, Alabama, Sept. 23, 2021. Dive training allows the Marines with 3d Force Reconnaissance Co. to have multiple means of amphibious insertions, allowing them to conduct multi-domain reconnaissance, limited scale raids, or deny the enemy freedom of movement in designated areas. (U.S. Marine Corps photo by Cpl. Brendan Mullin)