China is a typical continental coastal country. The ocean plays an important strategic role in China's national defense construction and economic development. In recent years, China has been invaded by world powers from the sea for 479 times, including 84 large-scale invasions, with more than 860 invading ships and more than 470,000 troops. Almost all important ports, harbors and islands have been ravaged by foreign enemies. 2 1 century, China's strategic interests in the ocean direction have become more obvious, and the comprehensive realization of marine political, economic and military security has become a major strategic issue for the country. So protecting the ocean is to protect ourselves from infringement.