From Popular Science’s How 2.0, homemade spy sub – “Some fathers and sons play catch. Electrical engineer Jason Rollette and his 12-year-old son Trevor are a little more ambitious. Hoping to explore the lakes and rivers near their Milwaukee home, they’ve built their own underwater remote-operated vehicle, or ROV. Controlled and powered by a laptop, their ROV can swim more than a quarter of a mile, to depths of 250 feet, while a home-surveillance camera sealed inside sends a live feed to the pilots onshore.” – Link.