Via Yglesias, here's a pretty graphic and important description of exactly what we did when we were busy not torturing:

These memos show the CIA went much further than that with terror suspects, using huge and dangerous quantities of liquid over long periods of time. The CIA's waterboarding was "different" from training for elite soldiers, according to the Justice Department document released last month. "The difference was in the manner in which the detainee's breathing was obstructed," the document notes. In soldier training, "The interrogator applies a small amount of water to the cloth (on a soldier's face) in a controlled manner," DOJ wrote. "

By contrast, the agency interrogator ... continuously applied large volumes of water to a cloth that covered the detainee's mouth and nose." One of the more interesting revelations in the documents is the use of a saline solution in waterboarding. Why? Because the CIA forced such massive quantities of water into the mouths and noses of detainees, prisoners inevitably swallowed huge amounts of liquid - enough to conceivably kill them from hyponatremia, a rare but deadly condition in which ingesting enormous quantities of water results in a dangerously low concentration of sodium in the blood. 

Generally a concern only for marathon runners , who on extremely rare occasions drink that much water, hyponatremia could set in during a prolonged waterboarding session. A waterlogged, sodium-deprived prisoner might become confused and lethargic, slip into convulsions, enter a coma and die. Therefore, "based on advice of medical personnel," Principal Deputy Assistant Attorney General Steven Bradbury wrote in a May 10, 2005, memo authorizing continued use of waterboarding, "the CIA requires that saline solution be used instead of plain water to reduce the possibility of hyponatremia." 

The agency used so much water there was also another risk: pneumonia resulting from detainees inhaling the fluid forced into their mouths and noses. Saline, the CIA argued, might reduce the risk of pneumonia when this occurred. "The detainee might aspirate some of the water, and the resulting water in the lungs might lead to pneumonia," Bradbury noted in the same memo. "To mitigate this risk, a potable saline solution is used in the procedure." That particular Bradbury memo laid out a precise and disturbing protocol for what went on in each waterboarding session. 

The CIA used a "specially designed" gurney for waterboarding, Bradbury wrote. After immobilizing a prisoner by strapping him down, interrogators then tilted the gurney to a 10-15 degree downward angle, with the detainee's head at the lower end. They put a black cloth over his face and poured water, or saline, from a height of 6 to 18 inches, documents show. 

The slant of the gurney helped drive the water more directly into the prisoner's nose and mouth. But the gurney could also be tilted upright quickly, in the event the prisoner stopped breathing. Detainees would be strapped to the gurney for a two-hour "session." During that session, the continuous flow of water onto a detainee's face was not supposed to exceed 40 seconds during each pour. 

Interrogators could perform six separate 40-second pours during each session, for a total of four minutes of pouring. Detainees could be subjected to two of those two-hour sessions during a 24-hour period, which adds up to eight minutes of pouring. But the CIA's guidelines say interrogators could pour water over the nose and mouth of a detainee for 12 minutes total during each 24-hour period. 

The documents do not explain the extra four minutes to get to 12. Interrogators were instructed to pour the water when a detainee had just exhaled so that he would inhale during the pour. An interrogator was also allowed to force the water down a detainee's mouth and nose using his hands. "The interrogator may cup his hands around the detainee's nose and mouth to dam the runoff," the Bradbury memo notes. "In which case it would not be possible for the detainee to breathe during the application of the water."