U.S. Marine Corps Staff Sgt. Tremaine McCallum, Marine

U.S. Marine Corps Staff Sgt. Tremaine McCallum, Marine Combat Instructor of Water Survival, Support Battalion, Recruit Training Regiment, talks to recruits at the combat training pool on Marine Corps Recruit Depot, Parris Island, S.C., June 13, 2017. After demonstrations, recruits are tested on their ability to jump into deep waters, shed proper equipment, and tread water in full utilities as part of their swim qualification. (U.S. Marine Corps photo by Lance Cpl. Sarah Stegall/Released)