U.S. Marine Corps Staff Sgt. Andrew Slater, a Marine

U.S. Marine Corps Staff Sgt. Andrew Slater, a Marine Corps Instructor of Water Survival, Support Battalion, Recruit Training Regiment, instructs recruits how to swim during Swim Qualification at the Combat Training Tank on Marine Corps Recruit Depot, Parris Island, S.C., March 6, 2018. As a graduation requirement, swim qualifications are for recruits to be tested on their ability to jump into deep waters, shed proper equipment, swim 25 meters and tread water in full utilities to simulate an evacuation of a ship. (U.S. Marine Corps photo by Cpl. Sarah Stegall/Released)