The reasons span the work-life spectrum. The demands on a nuclear engineering trained submarine officer. The strain of balancing careers with a spouse who's also a military officer. A lingering sense of disgust after the submarine video scandal.
In addition to normal growing pains from integrating the force, the Silent Service also took a major blow last year when reports surfaced that female officers and visiting midshipmen had been filmed while getting in and out of the shower aboard the sub Wyoming.
However, that controversy isn't the driving force for many of the women.
"I would probably expect that most of the women are going to get out," Lt. Jennifer Carroll told Navy Times. "I don't know exactly what everyone's personal reasons are for it, but I think a lot of it has to do with co-location."
The number of women who re-up for undersea service is a crucial test to assess whether the five-year integration effort will be sustainable and will yield enough women to serve as department heads, and eventually submarine skippers, to make the sub force appealing to young women. Officials expect original cadre's take rate to hover around the force-wide average for female line officers of 18 percent.
"Regardless of community or gender, committing to a department head tour requires dedication and sacrifice by our junior officers and their families," SUBFOR spokesman Cmdr. Tommy Crosby said in an email. "Submarine force leadership remains committed to mentoring our junior officers, male and female, as they face this challenging decision."
Of the original 24 women selected to become nuke submariners, three have signed up for their department head tour, according to Submarine Forces spokesman Cmdr. Tommy Crosby, and the window for taking the bonus is still open.
When assessing officer retention, Crosby said officials factor in losses and time served.
Factoring in those unplanned losses leaves the retention rate at 16 percent for the first submarine officers, Crosby said.
The actual retention rate is about 16 percent, when you factor in unplanned losses, because the Navy only calculates retention rates on officers in the community who have reached three years of commissioned service.
***TK aviation and SWO numbers***
"Regardless of community or gender, committing to a department head tour requires dedication and sacrifice by our junior officers and their families," Crosby said in an email. "Submarine force leadership remains committed to mentoring our junior officers, male and female, as they face this challenging decision."
But within those communities is a great disparity. While 41 percent of male SWOs stick around, about 22 percent of their female colleagues do.
"I think our career path is really unique, too," she said. "We're opening more ports. We've got Kings Bay, Bangor, Groton. We're working on Pearl Harbor."
There are also stresses unique to being a so-called pioneer, she added.
"Any female in the military can probably speak to this, that being a demographic minority or looking different from all the people you work with, there's a spotlight on you," she said.
The sub force is trying to head off some of those issues with the integration of enlisted women, she said, by keeping the ratio to about 20 percent.
"I think there already is kind of a perception that we're special or different or there's something big going on here," she said. "I think everybody feels that quite clearly. So downplaying that, I think that made the transition easier for me."
Sweetening the deal
Among them is a fully-funded, in-residence graduate school program, expansion of the service's career intermission program and — in the future — getting rid of officer year groups altogether.
Officers can take up to three years off with CIP to raise children, or possibly work in new parenthood during a graduate school stint. But for those staying on active-duty, the Navy extended both installation child care hours and maternity leave this year.
Eighteen weeks of maternity leave sounds great in theory, one female officer told Navy Times, but there are still concerns about how it will affect careers.
"It's nice, but I don't know anybody who could spend four months away from their job and still do well," said the designated helicopter pilot, who asked not to be named out of concern for her career.
"Maybe on the up-and-up it's not supposed to, but if you've got somebody who doesn't spend four months away from work and you've got somebody who does, and you're saying, 'Okay, which one am I going to rank higher?' You know?" she added.
Still, Carroll said, she's optimistic about the future of women on submarines.
"When you look at the first year group going through, I think there is more friction associated," she said. "I would expect the numbers in the first couple year groups to be lower anyway."
"The idea of going back to a fast-attack is exciting, but the other piece of that is just it's a really demanding job," she said.
"So when you want to prioritize your family, you really have to decide if you're willing to go back to that demanding lifestyle."
David B. Larter was the naval warfare reporter for Defense News. Before that, he reported for Navy Times.
Meghann Myers is the Pentagon bureau chief at Military Times. She covers operations, policy, personnel, leadership and other issues affecting service members. Follow on Twitter @Meghann_MT