Reply #3: No, not true. There are videos of waterboarding out there, and

[soothsayer]

what they do is lay you down with your head lower than your chest, then force a balled up wet rag over your nose and mouth so it's hard to breathe and you keep breathing in water vapor, and they keep pouring more water on the rag and as you get panicky they pour more on it and on you so now you feel like you are drowning, so your chest gets real tight and your heart races and you get all panicked and are struggling, then they let you gasp a lungful of air and start it all over again.

We actually have reflexes that prevent water entering the lungs very easily. Wikipedia puts it like this

The reaction to water inhalation

If water enters the airways of a conscious victim the victim will try to cough up the water or swallow it thus inhaling more water involuntarily. Upon water entering the airways, both conscious and unconscious victims experience laryngospasm, that is the Larynx or the vocal cords in the throat constrict and seal the air tube. This prevents water from entering the lungs. Due to this laryngospasm, water enters the stomach in the initial phase of drowning and very little water enters the lungs. Unfortunately, this can prevent air from entering the lungs, too. In most victims, the laryngospasm relaxes some time after unconsciousness and water can enter the lungs causing a wet drowning. However, about 10-15% of victims maintain this seal until cardiac arrest, this is called dry drowning as no water enters the lungs. In forensic pathology water in the lungs indicates that the victim was still alive at the point of submersion; the absence of water in the lungs may be either a dry drowning or indicates a death before submersion.

http://en.wikipedia.org/wiki/Drowning

On edit, here's wikipedia's description of waterboarding;
The prisoner is bound to an inclined board, feet raised and head slightly below the feet. Cellophane is wrapped over the prisoner's face and water is poured over him. Unavoidably, the gag reflex kicks in and a terrifying fear of drowning leads to almost instant pleas to bring the treatment to a halt. According to the sources, CIA officers who subjected themselves to the water boarding technique lasted an average of 14 seconds before caving in. They said al Qaeda's toughest prisoner, Khalid Sheik Mohammed, won the admiration of interrogators when he was able to last over two minutes before begging to confess.<3>

snip

BUT...looky, it can have long lasting effects:

The physical effects of poorly executed waterboarding can be extreme pain and damage to the lungs, brain damage caused by oxygen deprivation and sometimes broken bones because of the restraints applied to the struggling victim. The psychological effects can be longlasting.

Dr. Allen Keller, the director of the Bellevue/N.Y.U. Program for Survivors of Torture, has treated "a number of people" who had been subjected to forms of near-asphyxiation, including waterboarding. An interview for The New Yorker states:

argued that it was indeed torture. Some victims were still traumatized years later, he said. One patient couldn't take showers, and panicked when it rained. "The fear of being killed is a terrifying experience," he said.<8><9>

much more here http://en.wikipedia.org/wiki/Waterboarding