http://www.blacklistednews.com/news-4136-0-3-3--.html

That's a pretty heavy precaution taken for supposed simulated drownings

Additionally, Sifton notes the CIA may have had some close calls with detainees nearly dying during interrogations: the May 10, 2005, Bush Administration torture memo by Stephen Bradbury notes that doctors were nearby to perform a tracheotomy if during waterboarding the suspect is approaching death.