Please open you mind and allow me to educate you.
I'm a SERE Graduate from 1978...Warner Springs CA.
First, in any given SERE class, even back then, no more than 2-3 of 40-50 were subjected to the Waterboard. Of those, each and every one has some degree of PTSD and many are on 100% VA disability.
It permanently rewires your brain. Nobody comes away without damage, including those who apply it.
It is nothing like what you see in the movies as an actual depiction would reveal classified information.
It is now forbidden in EVERY US Military training environment. Warner Springs was the last hold-out. All other facilites banned it back in the 80s/early 90s.
Sorry,I am often full of crap. I did think that it might cause mental damage but with the Muzzies how could you tell?