A sail is any type of surface intended to generate thrust by being placed in a wind—in essence a vertically-oriented wing. Sails are used in sailing. History of sails The ships built at around 10,000 BCE were just crude log rafts or dug-out canoes. The earliest known ships were papyrus reed boats built by the Egyptians around 4,000 BCE. The Greeks and Phoenicians had begun trading by ship around 1,200 BCE. The Arabs had invented the sail in about 2,000 BCE in an attempt to establish tradi… (More on Sail)