Zhang Wuyi sits in his double-seater submarine during a test operation at an artificial pool near a shipyard in Wuhan, Hubei province May 7. Zhang, a 37-year-old local farmer, who is interested in scientific inventions, has made six miniature submarines with several fellow engineers, one of which was sold to a businessman in Dalian at a price of 100,000 yuan ($15,855) last October. The submarines, mainly designed for harvesting aquatic products, such as sea cucumber, have a diving depth of 20-30 metres, and can travel for 10 hours, local media reported.

Zhang Wuyi smokes a cigarette as he prepares his double-seater submarine for a test operation at an artificial pool near a shipyard in Wuhan, Hubei province May 7.

Zhang Wuyi sits in his double-seater submarine during a test operation at an artificial pool near a shipyard in Wuhan, Hubei province May 7.