Cruise-Ship-Balcony-Door-Debate (11:15 a.m. EST) -- We recently stumbled upon an interesting debate on the Cruise Critic message boards. The question: Do you sleep with your balcony door open?

Members argued their claims for more than a half-dozen pages, some insisting that an open door makes for a more pleasant experience, others chastising them for disregarding cruise line policies.

"It's against the rules," said member jamscckmc.

Paul65 agreed: "Generally not a good idea to leave the balcony door open, but these threads pop up from time to time, and there are always a certain number of people who have the attitude of, 'I'll do whatever I want to do in MY cabin.'"

Additionally, 38 percent of the more than 2,500 people who voted in a subsequent Cruise Critic Daily Poll said they don't do it because it's against the rules, while just 16 percent said they always do it.

So what's the deal? Are the naysayers correct? Is it really a no-no to snooze (or shower, or read or, well, anything) with your balcony door open? We contacted several lines to find out, hoping to settle this conundrum once and for all. Not surprisingly, we got a range of responses.

Save energy, and keep them closed.

"We do respectfully ask passengers to maintain a comfortable climate in their stateroom, to please keep their balcony door closed -- there is a sign posted on the balcony door," says Princess spokeswoman Karen Candy. "In warmer climates, leaving the balcony door open can impact the efficiency of the onboard air conditioning system."

"As a standard practice we ask that guests close their balcony doors as it affects our air-conditioning system if the doors are left open for an extended period of time," adds Royal Caribbean spokeswoman Janet Diaz.

Carnival rep Vance Gulliksen agrees: It's "not necessarily against the rules but something that is not encouraged," he says. "There is signage next to the balconies discouraging guests from leaving the balcony doors open."

In addition to affecting sleeping conditions in the room with the open door, passengers may also affect the air-conditioning in surrounding rooms if they leave their balcony doors open overnight, thereby negatively impacting the experience of others, says Holland America's Mary Schimmelman.

According to Schimmelman, the prolonged opening of balcony doors also causes more drag and less aerodynamic movement when the ship is sailing, meaning that it takes more fuel to propel the ship forward. She adds that "keeping balcony doors closed can cut costs, and we can then pass on those cost savings" to passengers -- in the form of reduced cruise fares.

She also added that HAL, on a few of its ships, has beta-tested technology that automatically shuts off cabin air-conditioning when balcony doors are opened. But, at this point, the line's use of said technology is still not official or fleetwide.

Protect yourself, and keep them closed.

In the original Cruise Critic thread on the subject, numerous members mentioned safety concerns when it came to leaving verandah doors open -- including bad weather, wildlife and "wind tunnels" that can be created when the main cabin door and the balcony doors are ajar at the same time. They're not alone.

"We discourage the practice [of leaving balcony doors open]," says Celebrity spokeswoman Tavia Robb. "Guests in staterooms with verandas are expected to use common sense in ensuring their own safety, security, and comfort. Should the ship encounter wet weather or other conditions while the guest is sleeping, safety concerns could become an issue."

Further comments from our Facebook page support Celebrity's stance. Janet Murray, who says a bird flew into her cabin one night, still keeps her door open but makes sure to close the sheer curtains to keep out any unwanted visitors of the winged variety.

Julie Scarbrough keeps her door shut tight at night for a different reason: "I'm a sleepwalker and that would not end well."

Hmm. Good question, but we don't have a policy.

Norwegian Cruise Line seems to take a slightly looser stance on the issue. "It's up to the guest, but we don't have any formal rules on this," says line representative Courtney Recht.

Actually, most of the lines echoed that sentiment, stating things like "no rules, no strict penalties" (Holland America) and "[we don't] have a written, enforceable policy against guests sleeping with their veranda doors open" (Celebrity).

Bottom line: There IS no bottom line.

Nearly all of the cruise lines that responded said they try to discourage passengers from leaving balcony doors open, as it can impact the ship's climate control, but none of the lines specifically said "it's against the rules."

Still, we'd advise using common sense. If you're thinking about leaving your balcony door ajar while you catch some Z's, be smart about it, know your line's official policy on the subject (if there is one), and be prepared to comply if you're asked by crewmembers to close the door, as you may be affecting the comfort of other passengers.

--by Ashley Kosciolek, Copy Editor