Most things that you’d consider rugged and able to stand up to the elements usually turn soggy and short out when submerged twenty feet under for hours on end. That’s why you’ll pay top dollar for a fancy divers watch. It’s also why you’ll spend upwards of $100 for a quality dive light. Inspired by the amazing characteristics of perfluorocarbon, Dave over at Mechanical Mashup decided to build a DIY dive light by submerging a cheapo LED flashlight from the hardware store in mineral laxative to achieve neutral pressure within the enclosure. In doing so he also isolated the electronics in a non-conductive liquid, further protecting it in those murky depths. [Thanks, Ben!]