Isn't the water in waterboarding actually like "breathable" but it's mostly the mind that convinces the body you are drowning?
Well they're spraying water on your face, so yeah you can breathe but you're going to get some water in your respiratory system no matter what. You're not immediately drowning but if they keep it up you may.
Although it's usually done with a cloth or something like that covering the captive's face so you're safe for the most part. The above example is a worst case scenario.
