Zhang Wuyi's homemade submersible is tested on Moshui Lake in Wuhan. The 4.6 metre long submarine was built using parts from a small yacht and took Zhang and his friends 25 days to build. According to Zhang the submarine can travel for 20km/h for 10 hours. Zhang used to be the apprentice of Li Yuming, a local renowned submarine enthusiast who built 7 submarines in the past five years.