A U.S. Marine Critical Skills Operator with 1st Marine Special Operations Battalion, Marine Corps Forces, Special Operations Command, releases his ruck sack from his body, preparing to land during a double-bag static line parachute training course , Aug 26, 2014, in rural Arizona. The course was an introduction to the High Altitude, High Opening insertion method utilized by Special Operations Forces. - A U.S. Marine Critical Skills Operator with 1st Marine Special Operations Battalion, Marine Corps Forces, Special Operations Command, releases his ruck sack from his body, preparing to land during a double-bag static line parachute training course , Aug 26, 2014, in rural Arizona. The course was an introduction to the High Altitude, High Opening insertion method utilized by Special Operations Forces.