U.S. Navy Petty Officer 3rd Class Ryan Walker, foreground, demonstrates to Sri Lankan Marines the proper way to apply a dressing to a wound during the tactical casualty combat care portion of a military tactics training and exchange, part of a theater security cooperation engagement at Welissara Naval Base, Sri Lanka, March 29, 2017. Walker is a hospital corpsman assigned to 1st Battalion Landing Team, 4th Marines, 11th Marine Expeditionary Unit. Marine Corps photo by Cpl. Devan K. Gowans