【How-to】How does waterboarding work - Howto.org

The water pour could last up to 20 seconds, then be paused, then another 20 seconds, paused, then 40 seconds. The subject feels as though he is drowning. Typically, the subject spasms, expels water and snot, , sometimes vomit, squirms and flops on the gurney as if having a seizure.