Submariners sleep nine to a bunk room. There are four showers and seven toilets for the roughly 140 enlisted men. The passageways on board the vessel are so narrow that crew members can barely squeeze by each other without touching.

And that's on the roomiest submarines.

The Navy is considering allowing women to serve aboard submarines for the first time, 16 years after bringing female sailors onto surface combat ships.

Some sailors and wives warn that putting men and women together in extremely close quarters underwater for weeks at a time is just asking for sexual harassment cases and wrecked marriages. But supporters of the idea say it is a matter of fairness and equal opportunity, and what worked on ships can work in subs.

"There's just a whole lot less privacy on board a submarine," said retired Navy Capt. Mike McKinnon, commanding officer of the Kings Bay sub base near St. Marys from 2004-07 and a former skipper of the submarine USS Kentucky. "But I think grown adults and professionally minded people can deal with those issues."

Over the past two weeks, top leaders at the Pentagon have said they are considering ending another in the dwindling number of military specialties reserved for men only. Officials said a decision could come soon, and women could be aboard subs by 2011.

The Navy will have to work through a host of issues first. Would men and women get separate bathrooms and sleeping quarters, as is already done aboard surface ships? Would the process of integrating subs begin with female officers, followed by enlisted women? What would happen if a woman discovered at sea that she was pregnant?

"If women can be on space shuttles and on surface ships, I think they ought to be able to work on submarines," said Lisa Goins, who retired in February after a 20-year Navy career. She served aboard aircraft carriers and at the prison at Guantanamo Bay, Cuba.

Kings Bay is the East Coast base for the Navy's Ohio-class submarines, which are armed with Trident nuclear missiles and go on 77-day tours of duty underwater. The 18 Ohio-class subs would probably be the first to take on women since they are the largest in the undersea fleet, 200 feet longer than the Navy's fast-attack submarines.

Still, at 560 feet, Ohio-class subs are a tight fit for their 160-man crews. Sailors sleep in cramped bunk rooms roughly the size of walk-in closets. The 140 enlisted men share two bathrooms. (The officers have separate facilities.)

The passageways and hatches are so narrow that those aboard are always rubbing up against each other — a situation played for laughs in the 1959 Cary Grant comedy "Operation Petticoat," in which a World War II sub rescues a group of stranded Army nurses.

The Associated Press sought permission to interview sailors at Kings Bay about the potential policy shift, but after a week, the Navy had yet to give its approval. Sailors contacted outside the base would not comment.

On blogs and online networking sites, wives of submariners have warned that the close contact could lead to sexual temptation and other complications.

"I completely believe this would put strain on some relationships because there are trust issues," said Jennifer Simmons, whose husband serves on a submarine at Kings Bay. "It's asking for sexual harassment cases left and right. If you're trying to go through a passageway together, guess what — you're going to touch."

The Navy bans "fraternization" between unmarried men and women. Punishment can range from a letter in the offender's file to a court-martial. Navy officials said they had no immediate figures on reports of fraternization aboard its ships.

The rule change that allowed women to serve on combat ships was pronounced a success by the Navy long ago. But it was not all smooth sailing.

In the mid-1990s, the aircraft carrier Eisenhower was nicknamed "The Love Boat" after 15 women became pregnant and a man videotaped himself having sex with a woman. However, the Navy said 12 of the women who conceived did so before boarding the ship, and the three others got pregnant during shore leave.

Officials said the paperwork for changing the policy on submarines is being drawn up and could be finished by the end of the month or early November, after which it would be sent up the chain of command and then to Defense Secretary Robert Gates for his approval. If Congress wants to block the move, it must pass legislation.

Key military leaders have already said they favor changing the policy that has allowed women on all surface ships since 1993 but still bans them from submarines. Women are allowed to serve on subs in a few countries, including Australia, Canada, Norway, Spain and Sweden.

McKinnon, the former base commander, said he suspects unhappy spouses would be the biggest obstacle to a change in policy. He acknowledged that sailors serving undersea together for weeks without surfacing form close bonds.

"I think there's this concern that if you have women out there, they're going to develop feelings for each other and have bad things happen," McKinnon said. "I think that's a natural thought. But the surface Navy's come through it."

He added: "You work with women in the workplace. You should be able to work with them on submarines."