That's a pretty cool video, I wonder what the purpose of the aluminum barrel extension is?

It’s some manner of custom underwater suppressor. Neat video that’s been posted here and there over the years. It looks like soooooo much fun, and doing something good for the local ecosystem since those invasive buggers are so destructive. I really want to try that at some point, but I just don’t see it happening for me.

I am curious as to how well the suppressor works under water. Water conducts sound better than air. I would think the risk of hearing damage would increase under water....But this still is so neat!