Malcolm Wrightson Nance, a counterterrorism specialist who taught at the Navy's Survival, Evasion, Resistance and Escape (SERE) school in California, likened waterboarding to drowning and said those who experience it will say or do anything to make it stop, rendering the information they give nearly useless.

"In my case, the technique was so fast and professional that I didn't know what was happening until the water entered my nose and throat," Nance testified yesterday at a House oversight hearing on torture and enhanced interrogation techniques. "It then pushes down into the trachea and starts the process of respiratory degradation. It is an overwhelming experience that induces horror and triggers frantic survival instincts. As the event unfolded, I was fully conscious of what was happening: I was being tortured."

Nance's testimony came as Democrats on Capitol Hill press for an outright ban on the technique and others like it that have been used by the CIA in interrogating terrorism suspects. Unlike attorney general nominee Michael B. Mukasey, who called the technique repugnant but declined to say whether it is torture, Nance said unequivocally that waterboarding is a long-standing form of torture used by history's most brutal governments, including those of Nazi Germany, Imperial Japan, North Korea, Iraq, the Soviet Union and the Khmer Rouge of Cambodia.

House members and senators have responded to the controversy by introducing legislation that would extend a ban on severe interrogation tactics by military personnel to all employees of the U.S. government, including the CIA's.

At a House Judiciary subcommittee hearing yesterday, Nance and Air Force Col. Steven Kleinman, a senior intelligence officer with decades of experience, said waterboarding is an ineffective tool for gathering information. Nance said that waterboarding sets off a fear of impending death and that people will say anything to get out of it.

Rep. Trent Franks (R-Ariz.) contended at the hearing that sometimes severe techniques need to be used in emergencies and against the nation's top enemies, such as Khalid Sheik Mohammed, the Sept. 11, 2001, attacks' alleged architect, who was subjected to waterboarding in CIA custody. Franks said that Mohammed experienced just 90 seconds of waterboarding and gave up important information about al-Qaeda.

Nance disputed Franks's assessment, saying that Mohammed probably knew how to resist and gave up information that would appear to be a "gold mine" to his interrogators but instead was "trash" for him and al-Qaeda.

If Mohammed faced waterboarding for 90 seconds, Nance said, about 1.2 gallons of water was poured down his nose and throat while he was strapped to a board. Nance said the SERE school used a board modeled after one from Southeast Asia, though it had leather straps instead of metal clamps.

SERE attendees expect to be released and assume that their trainers will not permanently harm them. Nance said it is "stress inoculation" meant to let U.S. troops know what to expect if they are captured. "The SERE community was designed over 50 years ago to show that, as a torture instrument, waterboarding is a terrifying, painful and humiliating tool that leaves no physical scars, and which can be repeatedly used as an intimidation tool," he said.

A detainee, on the other hand, "has no idea what is about to happen to them," Nance said, and could legitimately fear death. "It's far worse," he said.