Homemade helicopters, replica tanks and biplanes built from scratch: These are just some of the many whacky products cranked out by China’s less-celebrated innovation sector, the amateur inventor, often an old farmer or enthusiast with too much time (and money) on their hands. Here, we pay tribute to those dedicated inventors who have toiled away in obscurity often just to make someone on Weibo go, “Huh, cool.”

The Submariner

Laid off from a textile factory in 2008, Wuhan-based Zhang Wuyi decided to keep his head above water by going into the submarine-building business. Zhang’s wrought iron dual-seat miniature subs can reach 20 kilometers per hour, and dive 30 meters below sea level for up to 10 hours, which has proved useful for combing the seabed for prized products like sea cucumbers and shellfish. A Dalian businessman bravely paid 100,000 RMB (15,855 USD) to become Zhang’s first customer and was delighted to catch 50 kilos of cucumber in 40 minutes, using the sub’s robotic claw and underwater cameras.

Zhang’s submariner startup uses a fin-tail patent by Li Yuming, a pioneer of the amateur sub-building trade from Anhui province, whose Twilight No. 1 was completed in 2005. Since then, numerous fellow farmers have joined the field with their own self-built submersibles, including 44-year-old Tan Yong, who built a 1,000-kilogram vehicle capable of diving 10 meters, and Anhui’s Zhang Shenwu who built a six-meter, two-ton torpedo capable of slipping just a single meter below the waves—but cost less than a bomb, at only 5,000 RMB. Now with over 10 employees and a workshop, Zhang Wuyi has found a niche market that looks certain to keep swimming along.