Maybe you have to be a real science geek to enjoy this. Don't know. But I found it fascinating. Video and explanations of shooting a rifle under water. Not in self-defense, of course, just to see what it looks like and better understand how the weapon works.
[video=youtube;cp5gdUHFGIQ]https://www.youtube.com/watch?v=cp5gdUHFGIQ[/video]
[video=youtube;cp5gdUHFGIQ]https://www.youtube.com/watch?v=cp5gdUHFGIQ[/video]