The ever-ingenious Destin at SmarterEveryDay built a underwater periscope so he could film an AK being fired underwater with a super-ultra-high-end high speed camera that is not waterproof (and probably costs a little less than $1,000,000 to buy outright).

I can’t wait for his next video which will cover Russia’s frogmen guns.

Thanks to OpenSourceDavid for the tip.