When three Chinese scientists plunged to the bottom of the South China Sea in a tiny submarine early this summer, they did more than simply plant their nation’s flag on the dark seabed.

The men, who descended more than two miles in a craft the size of a small truck, also signaled Beijing’s intention to take the lead in exploring remote and inaccessible parts of the ocean floor, which are rich in oil, minerals and other resources that the Chinese would like to mine. And many of those resources happen to lie in areas where China has clashed repeatedly with its neighbors over territorial claims.

After the flag planting, which was done in secret but recorded in a video, Beijing quickly turned the feat of technology into a show of bravado.

“It is a great achievement,” Liu Feng, director of the dives, was quoted as saying by China Daily, an English-language newspaper, which telegraphs government positions to the outside world.