Officer Training Camp, in Quantico, Virginia, is more of the same rigorous physical training as Initial Training, with the added purpose of identifying true leaders. “Where Boot Camp is about breaking down individuals and then building up teams, Officer Training is about weeding out those who cannot lead,” Brad Ohlund, the film’s Director of Photography, says. “You can be the greatest rifleman in the Marine Corps, but if you’re not a leader, then you have no place as an officer.”

In the jungle-like terrain of Quantico, Virginia, officer candidates conduct mock “force-on-force” exercises. For the crew, the set-up was reminiscent of an amped-up version of forest Paintball, but for the Marines, it is all too real. “This is a group of people mastering skills they need if they expect to survive in a real battle,” Ohlund says. “Everyone was viscerally aware that they were creating neurological and muscle memory that they could use in real-life situations.”

The crew was repeatedly reminded about how dedicated the Marines are to producing the finest fighting force in the world. Primary wartime experiences that shaped training protocols over the decades have allowed this elite force to be as ready for anything as soldiers can be. This was no more evident than when officer candidates were nearing the end of their training. It was time for “the Quigley,” a water course that tests the mettle of anyone who faces it down. The Quigley was created by 1^st Lt. William Quigley, who was tasked in 1976 to prepare Marines for combat in Vietnam. He had served two combat tours in Korea and three in Vietnam; he knew that the course had to replicate real experiences in real jungles. According to Marine lore, Quigley’s assignment was to create a course where “each candidate should look like they tangled with two constipated pit bulls and lost.”

In the Quigley, fully-loaded Marines leap into and navigate obstacles through a swamp that can harbor water moccasins in summer and ice in winter. This exercise’s purpose is to force officer candidates to face fears and lead their peers through uncharted territory. Its capstone is a culvert, through which each officer candidate must pass. It’s narrow. It’s submerged. Each candidate is strapped with full gear, barely able to fit. Every officer remembers the Quigley.