From
Strategy Planet's Empire Pages :
"As early as the 8th and 9th centuries CE, China was using massive multi-deck ships for river and canal trade. With hundreds of crewmen (and women), who often were born, lived, and died on board these massive vessels, these ships plied the inland waters of the empire. Other, foreign ships would travel as far as Ceylon (modern Sri Lanka) from their ports in south China. Soon, the Chinese themselves began using similar large ships to ferry grain from south to north China, and by the 9th century the Chinese began building their own huge ocean-going ships, designed to extend the reach of the empires commercial and military power. Great battles soon followed, between rival Chinese factions and other Asian powers; in 1161, for instance, the Sung Dynasty defeated the Jin Empire in a massive naval battle off the Shandong Peninsula, gaining control of the East China Sea. The Sung themselves fell to the Mongols under Kubilai Khan in 1279, in a campaign where Mongol sea power played a large role.
The Mongol warships of the Yuan Dynasty in the 13th and 14th centuries had four masts, more than sixty individual cabins, and crews of over 300 men. These ships were trading, transport, and war vessels rolled into one. The Ming Dynasty which came into power in the later 14th century continued this maritime tradition at first. Around 1405, Admiral Zheng He led an expedition of some 37,000 men into the Indian Ocean, with a huge fleet of Chinese warships. The largest of these vessels were 500 feet long, up to five times the size of comparable Western ships of the era, and had watertight compartments, not introduced in West until four centuries later. This mighty fleet sailed unopposed throughout the Indian Ocean and southwestern Asian waters until 1433, a tribute to the might of China. Though the Chinese navy would thereafter begin to decline, at it apex its fleet of Flying Tigers, large warships that carried the spirit of the empire in their fore-and-aft rigged sails and large crews, was a force to be reckoned with.
Chinese battleships, those ocean-going junks of immense size and power, carried troops, traders, and diplomats, and sported cannon and soldiers for attack and defense. Powerful in battle, they were also most useful as spearheads of diplomatic forays or military invasions. Able to defend themselves, attack other fleets, and deposit troops onto unfriendly shores, the Flying Tiger Warships were a versatile and powerful addition to the Empires military system. Cresting the horizon in distant seas, a force of dozens or even hundreds of these vessels no doubt created fear and confusion in Chinas enemies, and impressed Chinas friends.
In Empires, the Flying Tiger is a tremendous unit, because it can both fight and transport an invasion force. You dont have to build and manage two types of units to mount an attack."
-Oz