How Six turned a bunch of actors into believable Navy SEALs

Esquire has an article by Eric Tegler about the new television show, Six:

In Six, the eight-episode drama series to debut on the History Channel, members of SEAL Team Six venture forth on a mission to eliminate a Taliban leader in Afghanistan, a mission that goes awry when they uncover an American citizen working with terrorists. The story may be fiction, but the actors must be believable as Navy SEALs. The man who took on this challenge is retired Navy SEAL and television producer Mitchell Hall.
SEAL Team Six— formally known as the Naval Special Warfare Development Group— is an elite among elites. This is the unit that took out Osama Bin Laden, and it's no easy task to join up. To begin with, three-quarters of candidates who go through basic SEAL training fail to qualify. Those who do make it may serve with a SEAL Team for several years before they're put forward as candidates to join Six, which weeds out more than half of those candidates.
The SEALs who make it through are the kind of unbreakable people that Hall must teach actors to emulate. "That shows the pedigree of Six," says Hall, who served with the team for five years in a twenty-year career in Naval Special Warfare, having deploying to Iraq and Afghanistan.
Accurately portraying the methods, gear, and operations of SEAL Team Six is hard enough. Conveying the complexity of the decisions its operators must make is probably impossible, Hall admits. "It's an imperfect effort by imperfect soldiers with imperfect policy and often, unclear guidance."
But Hall, along with series creators David Broyles (another military special operations veteran) and Academy Award nominee William Broyles, were determined to try, and to correct Hollywood's habit of getting the elite military wrong more often that right. To achieve that authenticity, they essentially put the cast through basic SEAL training and tactical training.
Last winter, Hall met Six' lead actors, Walton Goggins, Barry Sloane, Kyle Schmid, and Juan Pablo Raba, for the first time at dinner in Encinitas, California. The next morning he plunged the quartet into ten days of intense, immersive training at SEAL FIT, a business that models fitness and mental training on the basic Navy SEAL course.
In the first five days, the actors were put through a regimen like the first phase of SEAL training. They had to work as a team while deprived of sleep. They hauled logs through water, endured running courses, and generally suffered. "They bonded in a way very few casts do," Hall says. He likens the training to "throwing a bunch of eggs at the wall and seeing which ones do not break." In fact, the series executives were seriously concerned the exercise would break and embarrass the actors, calling several times to check up on them. Throughout the training, the actors referred to each other using their character names. "There were times where they forgot each other's real names for a moment," Hall reveals. "They all suffered, but they came out better for it."
Hall hastens to add that the actors' training was merely representative; it's not even close to the full gamut that real SEALs go through. Still, they talk eagerly about the experience, including the second five-day period that was dedicated to tactical training, handling real guns used by Six, and learning basic tactical movements and skills. The actors wore real body armor. They also wear it on camera, where its weight and strain and its effect on restricting one's movement are clear. "It continued the process of helping them get into the minds of these operators, how they think, what motivates them," Hall maintains. "Before a scene, I'd pull actors aside and say, 'For this scene, as an operator, this is what I might be thinking. Put your own stamp on that.'"
One perhaps surprising thing he works on with actors is dispelling any preconceived notions they might hold about SEALs— especially that they're the hulking, macho tough guys stereotypes you see in popular culture. "You could walk past someone from the Special Operations community and you probably wouldn't even know it. They're fairly normal, well-adjusted guys who have a mental compartment that allows them to do some pretty interesting things."
Such compartmentalization is at the heart of what Hall says he seeks to portray in Six, "the impossible balance between an operator's professional life and his personal life—trying to be a father, a husband, a team mate, and a brother. To go back and forth between those extremes is quite a task."
Making actors walk, talk, and act like Navy SEALs wasn't the only challenge Hall and the production staff took on. They obtained, often at great cost, the actual gear that Team Six uses. The team's clothing, helmets, boots, and other equipment are not standard issue. They're often experimental and vendors are reluctant to release them. Like real SEALs before a mission, the actors were responsible for checking each other's gear before a scene. (The series had no Navy cooperation, a facet of post-Bin Laden policy by the military.)
Audiences will ultimately judge how well Mitchell Hall, the cast, crew, and producers have done. "We want the non-military audience to appreciate what these operators— and their families, I can't stress families enough— go through to do this for the United States. The military audience will be tough, but I think they'll appreciate the minute detail we went into from the gear to the verbiage to the basic movement. We did our homework."
The actors have done theirs, Hall affirms. "They did an amazing job. They turned themselves inside-out to honor these characters. I told everyone including myself, 'We have to earn the right to tell this story."
The show begins on Wednesday, 18 January at 2200 Eastern and Pacific on the History Channel.

Rico says they've set the bar pretty high for this one...