Panokseons were propelled by both sails and oars. Of the two basic types of sail, square and lateen, the square gives a strong performance downwind but struggles windward, whereas the fore-and-aft lateen excels against the wind, though requiring a large crew to handle it. In the West, square sails were used in the galleys of Ancient Greece and the Viking longships, and the fore-and-aft variety as early as the Mediterranean dromons of the Middle Ages. When the Age of Discovery began in the fifteenth century, multiple-masted ships equipped with both types of sails eventually appeared. In Korea fore-and-aft sail equipped ships had been in use since the eighth century. The panokseon and turtle ship therefore had two masts by default, and their position and angle could easily be managed so that the sails could be used in all winds, whether adverse or favorable.