Last summer, YouTuber (and former NASA engineer) Mark Rober built the world’s largest NERF gun and terrorized his kids with it. This summer, Rober is getting into water sports, putting his specific brand of engineering to use building himself a custom Super Soaker. Where the original is hand pumped, Rober’s uses nitrogen tanks to propel jets of water, though Rober’s is still just a scaled up version of the original. Gas is still used to pressurized a tank of water and fire a stream at an unfortunate target. He provides plans for building your own, if you’re so inclined, but before you get to work, know a few things about the process. Rober’s a highly trained engineer who knows exactly what he’s doing, so if you are going to build this, find someone with the required engineering experience. Also, the water comes out at 272 miles per hour, so don’t let anyone stand too close to the nozzle. They might lose something important.