Money, it seems, is no longer an obstacle for mainland scientists carrying out research. So much so that one project under way at the China Ship Scientific Research Centre as been described as bu cha qian, a popular phrase meaning 'money is not a problem'. That project is to build a submarine capable of working on the seabed in some of the deepest parts of the ocean, says Zhao Junhai , a senior engineer at the centre. 'We are testing the submarine. It will leave the dock later this year or early next year. Our researchers will then be able to explore ocean depths that the Americans and Japanese are currently unable to reach - at 7,000 metres,' Professor Zhao said. 'Until then we are not a real sea power.' China has made rapid advances in the field of ocean science and technology in recent years, narrowing the gap between the country and the traditional seafaring nations. Researchers are no longer satisfied with trailing behind other countries - they want to take the lead. The submarine being built by the research centre has an inner titanium shell, and an exterior shell made of a special plastic. Professor Zhao's job was to develop the outer shell for the submarine. He had some tough requirements: it had to be able to withstand pressures of 700kg per each square centimetre and not lose its shape, it could not be thicker than 5 millimetres, and had to be light enough for an adult to be able to easily lift it with one hand. 'We were decades behind other countries when we started, and the realm that we were about to enter had not been visited by others. To find a path, we had to burn money,' Professor Zhao said. Almost every mainland research institute, from the highly secretive military laboratories to the research and development centres in companies set up by overseas returnees, contributed to the project by sending in samples of materials developed for some of the harshest environments on Earth and in space. However, all those materials were weakened by the extreme pressures of the deep sea, Professor Zhao said. 'We have spent thousands of hours in laboratories and millions of yuan to find out a way to prevent water molecules from getting into the material - a process that we thought to be the most important reason why the materials got 'soft'. And now we have it. I can't tell you the formula but the stuff looks no different from a piece of transparent, lightweight and ordinary plastic. It is the most beautiful plastic, in my opinion. I don't think other countries have it yet.' The submarine is not the only breakthrough that China has achieved in recent years. In January, mainland researchers built an outpost at Dome A - the highest point in Antarctica - to carry out research on climate change and the geographical structure of the continent and its mineral deposits. Li Xueyong , vice-minister of the Ministry of Science and Technology, said in 2006 the nation would dramatically increase the funding for the development of ocean-related science and technology. But the government is demanding return on its investment and that has put a lot of pressure on researchers, a professor at the Ocean University of China said. The university, in Qingdao , is renowned for its research in marine sciences. 'In most circumstances science is not a goose that lays golden eggs. Sometimes it does not lay an egg at all,' the professor said. 'But government officials like to see immediate benefits. The global financial crisis is making them more demanding. They are cutting budgets on programmes that don't look promising. It kills the science.'