A Chinese junk fishes in the harbor near Hong Kong. Junks have covered decks, lugsails, and long rudders, but no keel. Their compartmentalized hulls increase stability on the open ocean.
In China and other areas of Asia, shipbuilders had developed an entirely different, and many argue superior, sailing ship. The junk was a wooden, ocean-going vessel recognized for the ingenuity with which it was developed and its remarkable seaworthiness. The flat-bottomed craft was assembled on a bed of sandbags, which settled and shifted as they adjusted to suit the craft's growing weight. Junks have high sterns and square bows, and most carried four or more masts that sported sails made of fiber and later, of small pieces of cloth. The sails were stiffened with bamboo battens to improve their efficiency. Asian shipwrights made innovative use of bulkheads to strengthen the hull. These partitions also created a number of watertight compartments that enabled merchants to carry liquid cargo. Instead of using side oars for steering, junks had a hinged plate at the stern called a rudder, a technological innovation not regularly seen in European ships until about the 12th century.
By the 9th century, Chinese junks regularly plied coastal and open waters of China, Japan, and Southeast Asia, and by the 15th century, junks regularly traveled as far as East Africa. Among the junk's most famous accomplishments were the journeys of Chinese explorer Zheng He, who, between 1405 and 1433, made seven voyages across the Indian Ocean, the Arabian Sea, and the Red Sea commanding a fleet of about 200 junks. A kindred vessel was the lorcha, which had a European style hull but was rigged with the sails of a junk.