Is there a plan behind China's subs?

Some Chinese officers said that a future objective will be to patrol as far east as Hawaii.

A critical question is Chinese seamanship. A US naval officer has 500 years of seagoing experience behind him, with 250 years of British navy and 250 years since the ships of Salem plied the seven seas and John Paul Jones founded the US Navy.

US submariners, for their part, have 100 years of experience, since the early 20th century, to draw on.

In contrast, in 5,000 years of history, China has produced only one great sailor, Admiral Zheng He (鄭和), who sailed the Pacific and Indian Oceans in the 15th century.

Chinese submariners, hampered by the Sino-Soviet split and the chaos of the Cultural Revolution in the 1960s and 1970s, are just beginning to learn their craft with highly complicated vessels.

US military leaders, including Secretary of Defense Robert Gates, have for many months contended that the Chinese should be more open about their military intentions, including why they are expanding their submarine fleet.

Pointing to the surging Chinese economy that pays for the ships, a US submariner said: "I suppose they do it because they can."

Richard Halloran is a writer based in Hawaii.