In September, for the first time in history, Chinese warships passed through the Straits of Magellan (at the southern tip of South America). This has long been the only safe waterway between the Atlantic and Pacific for surface ships. The straits are a narrow coastal path weaving its way through offshore islands. South of that is the open sea and Drake’s Passage, which is an extremely violent patch of water that ships have learned to avoid.
The only other natural route between the Atlantic and Pacific is the Northwest Passage (off the north coast of Canada). But this is blocked by ice most of the time, while the Straits of Magellan are open all the time. That said, these straits have some of the harshest weather on the planet. The straits are close to the Chilean coast and Chile provides pilots (which are mandatory for the 2,000 or so ships taking this route each year) to safely guide ships through. The Chinese task force, on its way to visit Argentina, consisted of a destroyer, frigate, and a supply ship. Most (nearly 90 percent) of ships passing between the Atlantic and Pacific use the Panama Canal.
Earlier in the year (July) 5 Chinese naval vessels (two destroyers, two frigates, and one supply ship) achieved another first by circumnavigating Japan. This was the first time Chinese warships had done this. It happened as the ships were returning from joint naval exercises in Russia. Instead of returning directly to their bases, the Chinese task force plotted a course that took them completely around Japan, the first time Chinese warships have done that. The Japanese were not amused. http://www.strategypage.com/htmw/htsurf/articles/20131030.aspx