The first class of female recruits is a third of the way through training at Marine Corps Recruit Depot San Diego - part of a Congressionally mandated effort to become the last service to integrate boot camp.
Until this year, the Marines' other boot camp, Parris Island, South Carolina, was the only one that accepted women. Congress ordered the Marine Corps to fully integrate women into its training battalions at Parris Island by 2025 and at San Diego by 2028.
The first class of women at San Diego has gone through pool exercises and scaled obstacles in the confidence course. Soon they will move north to Camp Pendleton, where they will begin rifle training as part of the 13 weeks it takes to become a U.S. Marine.
One obstacle for their leaders is keeping these women in the Marines once they prove themselves, and then finding more women like them who want to be a part of the Corps.
"It's a profound transformation," says Lea Booth, who was a Marine from 2004 to 2009.
"I had a blast at boot camp. It's super hard, obviously. It's physical. It's challenging. You don't get a ton of sleep. You're always on the move."
Women make up close to 20 percent of the Navy. The number of women in the Marines is just under half of that. Despite foot-dragging on integrating boot camp, the last two commandants of the Marine Corps have publicly said they want to increase the number of women in the Corps.
Booth says one reason there aren't more women is because many of the most recognizable jobs in the Marine Corps - or Military Occupational Specialties (MOS) - had been closed to women.
"You can do every job that a guy does with a few exceptions in the Air Force," she said. "But the main MOS in the Marine Corps women couldn't do until recently. So I'm sure that's part of it."
The Corps was also the only service to fight the Secretary of Defense's decision to open all combat roles to women in 2015. Compared with the Army, a relative handful of women have combat roles in the Marines.
Out of 3,763 Marine recruiters nationwide, 83 are women. Sgt. Leah Engdahl runs the Poway, Cal. recruiting office, just outside San Diego. Most Marines come right out of high school, and she said their image of the Corps comes straight out of video games.
"'Call of Duty,' things like that, and seeing what's on TV," she said.
Most Marines don't spend their careers in the once-restricted combat roles, and the image actually makes it harder to recruit a broader pool of women.
One of Sgt. Engdahl's recruits is among the first class of women training in San Diego.
"She kind of had it set in her mind that she wanted to be a United States Marine," Engdahl said. "She was a little bit concerned about maybe the physical aspect of things. The way that I prepared her was we would actually meet here at the office twice to three times a week and we would physically train to get ready."
Another significant disincentive for women considering Marine Corps careers is the specter of sexual assault. The Marines typically lead the services in the number of assault and harassment allegations.
"In my first duty station, I was raped, and I was not supported by anyone in my unit," said Julie Weber, who started serving in 1996. "At least nobody whose opinion mattered."
Weber has a tattoo on her forearm of the Globe and Anchor, the symbol of the Marines. She got it after she left the Corps in 2012 following a second enlistment. As she struggled through law school, she wanted a daily reminder of what she could accomplish.
She said she grasps that it may be hard for non-Marines to understand the complicated bond that she still has with the Corps.
"I try to support people who need it," she said. "I don't think I was always this way, but the Marine Corps kind of made me that way," she said. "And I am strong because of them."
