The Geneva Conventions supposedly govern the way prisoners of war are treated by their captors:
https://en.wikipedia.org/wiki/Geneva_Conventions
I hope we are still a signatory to all four treaties in the Geneva Conventions. I do not believe that enhanced interrogation including water boarding is allowed. Resorting to water boarding shows impatience and ignorance in my humble opinion. I hope we will not torture our prisoners of war in the future.
Supposedly intelligence garnered via water boarding a HUMINT target was necessary to locate our arch nemesis, Osama bin Laden. bin Laden was hiding in essentially in the plain sight in Abbottabad, Pakistan. We sent members of SEAL Team 6 to assassinate the leader of the Islamic Revolutionary organization known as al-Qaeda. All the necessary intelligence came from a near onsite joint CIA-NSA observation and listening post. We lost a very valuable stealth helicopter in the operation.

