U.S. Marine Corps Staff Sgt. Dary Selgren (left) and

U.S. Marine Corps Staff Sgt. Dary Selgren (left) and Sgt. Eric Bergstrom, Marine Corps Instructors of Water Survival (MCIWS), Support Battalion, Recruit Training Regiment, supervise recruits 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)