A coercive interrogation method in which a prisoner is strapped to a board and pushed under water, and made to believe he might drown.
The CIA has used this technique against enemy combatants, including high-level operatives of al-Qaeda (in particular, Khalid Sheikh Mohammed), with the endorsement of the U.S. Department of Justice*. The FBI has directed its own agents not to be present during such interrogations, as it views the legality of water boarding and other coercive methods (which would not be allowed in criminal investigations of U.S. citizens) to be in question-- and prefers to preserve the "purity" of interrogations so that they can be used as evidence in criminal cases.
Water immersion has been a longstanding component of torture for centuries. However, references to the current use of water boarding in the American media refer to it as an extreme or harsh method of interrogation, but refrain from using the "T" word. This is likely due to the efforts of the White House to parse the word "torture," with counsel searching for legal loopholes in the U.S. Constitution, Geneva Convention, and other international treaties in order to condone current interrogation practices. Agencies such as Amnesty International and Human Rights Watch have no such qualms in describing water boarding as torture.
The term is also used in the press to refer to a technique involving dripping water into a wet cloth over a detainee's face. Apparently, this can bring on the sensation of near-drowning. (This method of interrogation appeared in a memo written by the Pentagon's general counsel, William J. Haynes II, on Nov. 27, 2002 and approved by Defense Secretary Donald H. Rumsfeld on Dec. 2, 2002 regarding techniques that could be used at the U.S. detention facility at Guantanamo Bay, Cuba. It was not approved as a technique, as later Rumsfeld memos clarified, but Haynes described the method as "legally available.")
* After intensive media scrutiny, in June 2004 the CIA has apparently stopped the practice pending further review by the Justice Department. Specific interrogation techniques, harsher than what standard military doctrine allows, have been approved for use by U.S. military intelligence (under the White House's legal determination that certain detainees are not prisoners of war but enemy combatants)-- but these are classified, so it is not known if this method is approved for military interrogations.
Bradley Graham, "Interrogation Tactics Evolved." Washington Post. 21 May 2004. <http://www.washingtonpost.com/wp-dyn/articles/A44078-2004May20.html> (16 June 2004)
James Risen, David Johnston, Neil A. Lewis. "Harsh C.I.A. Methods Cited in Top Qaeda Interrogations." New York Times. 13 May 2004.
William J. Haynes II. "Counter Resistance Techniques." Memo to Secretary of Defense Donald Rumsfeld. 27 November 2002. Accessed from Washington Post. <http://www.washingtonpost.com/wp-dyn/articles/A62516-2004Jun22.html> (2 July 2004)
Michael Hirsh, John Barry and Daniel Klaidman. "A Tortured Debate." Newsweek. <http://www.msnbc.msn.com/id/5197853/site/newsweek/> (16 June 2004)
Dana Priest. "Harsh Tactics of CIA Put on Hold." Washington Post. 27 June 2004. <http://www.washingtonpost.com/wp-dyn/articles/A8534-2004Jun26.html> (30 June 2004)
U.S. Department of Defense. "Working Group Report on Detainee Interrogations in the Global War on Terrorism: Assessment of Legal, Historical, Policy, and Operational Considerations." (Draft) 6 March 2003.