How often you take your phone underwater? If so, why?

Some of the best video I have from my honeymoon was taken on an iPhone while floating in the Pacific Ocean with my (new!) wife. I wasn't going to grab a GoPro or some kind of Ocean Case for a video camera, I had a phone in my hand.

It’s more about using it while it’s raining on my bike (attached to the handle). No need for a water-thight case so far.