There was an article about, oh, a year ago on a pro-war Internet forum, where an active scuba diver who was a hawk on waterboarding decided to try it out just as Hitchens did. He was fine with the first few "dippings"; his control taught to him by his diving managed to keep him out of panic. However, as the attack escalated, he reached a point where he said he was absolutely convinced that he was dying and that he could not retain control. I wish I could find the write-up, but it is gone from me now.
In Q&A from other forum members afterwards he said that he would say anything, do anything to prevent ever having to feel that sensation again. He could imagine no circumstances where he would be able to train himself into being able to withstand it. He found it a miracle that people with no training could keep their sanity through it. He also thought that it had gotten to him worse because his training kept it from clouding his mind until it was overwhelming.
