Already, attack submarines are at times asked to stay out longer than six months - extensions that can be trying for sailors who serve in tightly confined spaces with limited outside communication as members of the "silent service."
Vice Adm. John Richardson told the AP this week that keeping subs out longer is one of several options the Navy is considering as the number of attack subs is projected to continue dropping in the next decade and beyond.
"I think we're looking at all the options," he said. "As you try and maintain the same presence with fewer hulls, there are all sorts of variables in that equation. One would be extending deployment lengths. So that's certainly on the table."
Submariners are not alone in seeing deployments extended periodically, as two wars and evolving threats strain the entire U.S. military. A spokeswoman for the admiral, Navy Cmdr. Monica Rousselow, said it is impossible to say how long sub deployments might become because so many factors are involved.
Extending deployments permanently would save resources because the Navy could complete more missions with the nuclear-powered submarines that it has available. The fast-attack subs travel to far-flung corners of the globe for missions including intelligence gathering and firing missiles, but they can maintain a presence only for so long before making the time-consuming journey back to U.S. bases.
Navy contractors began stepping up submarine production this year, but pressure on the defense budget has raised uncertainty about future procurement. While some critics describe the multibillion-dollar vessels as costly relics of a different era, Richardson says submarines remain integral to America's nuclear deterrence strategy and the security of a nation that conducts the vast majority of its trade by maritime channels.
Enlisted crew members on the attack subs sleep six to a room, stacked in bunks areas barely larger than a closet, and navigate corridors so narrow only one person can pass at a time. The deployments are typically broken up by port calls, but they can remain at sea for weeks or months at a time. The bigger, roomier ballistic missile subs generally stay closer to their home ports and have shorter deployments.
Sailors in the elite, all-volunteer submarine force go through psychological screening to make sure they can cope with the tight quarters and extended time beneath the ocean's surface. Nobody with claustrophobic tendencies is allowed on board.
But retired submariners say the time at sea does take a physical and emotional toll, particularly when a mission is suddenly extended.
"You establish a battle rhythm in your mind where `Six months is how long I'll be' and then, if it becomes seven months, you have to shift your mind a bit," said retired Rear Adm. John Padgett III, who remembers a particularly grueling 7 1/2-month submarine deployment during the Vietnam War. "You get a little tired of it."
Deployments longer than six months are unlikely to cause problems for specially trained sailors, but they would probably entail challenges for their families, said Army Col. Tom Kolditz, a psychologist at the U.S. Military Academy at West Point.
"You can probably find business decisions in the community based on that six-month cycle. You can find various kinds of financial planning done on that six-month cycle. If you take something like that that people are used to and change it, it can create problems," said Kolditz, director of the military academy's Department of Behavioral Sciences and Leadership.
At Naval Submarine Base New London in Groton, support services are available to help sailors' families deal with prolonged deployments, said Beth Darius, a services facilitator for the base's Fleet and Family Support Center.
"We honestly try to tell them, `Yes, you have a fixed date, but remember that date can always change,"' she said. "We try to help them not cement that date, but I personally know how easy it is to get that date and count down, and then have it change on you."
Richardson said in the interview Wednesday that constraints on communication are part of the nature of submarining, but that the Navy is working to improve bandwidth on the vessels. He said sailors will be able to communicate with family members more than ever, although e-mail will remain available only when it can be sent without the risk of giving up the sub's location.
Beyond the strain on sailors and their families, U.S. Rep. Joe Courtney said, the longer deployments reflect an increasingly acute security problem. Although Navy contractors received approval this year to double production of Virginia-class attack subs to two a year, he said that will only slow the decline in the size of the fleet and will not fully replace older ships as they are taken out of commission.
The number of nuclear-powered attack submarines in the U.S. force has fallen from a peak of 98 in the late 1980s to 53 at the end of fiscal year 2010, a decline that roughly matches a drop in the overall size of the Navy since the end of the Cold War. Each Virginia-class attack submarine costs about $2.6 billion and carries a crew of roughly 135 officers and sailors.
Courtney, who is pushing for an increase in attack sub procurement, said they are unmatched in their ability to deliver firepower and do surveillance without being detected.
"Look at Libya. When President Obama said `unique capabilities,' what he was really referring to was the USS Scranton, the Providence and the Florida, which in a matter of an hour obliterated Gadhafi's air defenses," said Courtney, a Democrat whose eastern Connecticut district includes the sub base and the Groton headquarters of the Navy's primary submarine contractor, General Dynamics' Electric Boat.
Currently, the submarine force can accommodate only about half the support requests from combatant commanders, according to Richardson, who said sub deployments are currently extended a month or more to meet demands on a case-by-case basis. He noted that surface ships also face extended deployments, as all branches of the military contend with increased demands.
As the Navy deals with rising security demands and budget pressures, he said, the force is also looking into repositioning submarines around the globe to reduce transit times and pressing builders to reduce maintenance periods and wring more deployments from aging vessels.