If that damn Kevin Costner movie ever comes true and humans eventually evolve to have gills, I want my offspring to spend their days frolicking under the waves on this device. It's called the "Subwing" and it toes you behind a boat underwater like a giant fishing lure. I guess it's probably not nearly as cool if you live in a place where the water's all murky and green and gross and you can't see submerged trees or rocks or whatever, but still, this looks so much fun. I MUST HAVE IT.

H/T: Reddit