US Navy (USN) Hospital Corpsman First Class (HM1) Eva Codizal explains the capabilities of a chemistry analyzer to the Surgeon General of the Navy Vice Adm. Donald Arthur on the U.S. Military Sealift Command (MSC) Mercy Class Hospital Ship USNS MERCY (T-AH 19), during the ship's five-month humanitarian and civic assistance deployment.(U.S. Navy photo by Mass Communication SPECIALIST SEAMAN Joseph Caballero) (Released)