A U.S. Marine Critical Skills Operator with 1st Marine Special Operations Battalion, Marine Corps Forces, Special Operations Command, executes a double-bag static line (DBSL) jump, during a DBSL parachute training course , Aug 26, 2014, conducted in rural Arizona. The DBSL course was an introduction to the High Altitude, High Opening (HAHO) insertion method utilized by Special Operations Forces. (U.S. Marine Corps Photo by Lance Cpl. Steven M. Fox/Released)