A Chinese farmer, Zhang Shengwu, living near the Yangtze River in Anhui province, has built a working submarine with a surprisingly low investment of around $5,570.
While many people have hobbies such as flying drones, collecting stamps, or building kit cars, Zhang's feat is rare - building his own personal submarine, which he calls Big Black Fish.
Zhang, who grew up along the Yangtze River, has a background in shipping, farming, carpentry, and welding, but had never worked on a submarine before.
He spent a decade constructing his own personal sub.
Author's summary: Chinese farmer builds working submarine.