A homemade "robot submarine" is put into the sea for tests in Yantai city, Shandong province on April 10. The submarine was made by Zhang Wuyi, 38, a laid-off worker in Wuhan city, Hubei province. Since he was laid off from a textile machinery factory in 2008, Zhang has been interested in small submarines. He has invested around 3 million yuan ($484,000) into the creation. After failing several times, finally he made several private submarines. The machine, 4.5 meters long, 1.6 meter wide and 4 tons heavy, can sink into 30-50 meters underwater and advance slowly by remote control. One has been ordered by an aquaculture company in Yantai.[Photo/Xinhua]