I've been meaning to make a video of the PH going off. I've fired it before, no big deal like ear pain or whatever you may be thinking. You can feel the concussion wave in your body and it's a bit scary the first time, that's it. How far away do you think this guy was when his PH went off?
http://spearfishing.world/106-post2.html
What caliber would that thing be? a 12 ga? Looks huge