Waterboarding torture in the USA

This video from the USA says about itself:

Public Waterboard Demonstration in DC

Waterboarding is a form of torture that consists of immobilizing a person on his or her back, with the head inclined downward, and pouring water over the face and into the breathing passages.Through forced suffocation and inhalation of water, the subject experiences the process of drowning in a controlled environment and is made to believe that death is imminent. In contrast to merely submerging the head face-forward, waterboarding almost immediately elicits the gag reflex.