Final answer:
Windward sails were present in China during the Ming Dynasty as part of the advanced shipbuilding that took place under the reign of Emperor Yongle, specifically during Zheng He's maritime expeditions that started in 1405. China's large treasure ships, designed for long-distance voyages, incorporated sails, sternpost rudders, and magnetic compasses.
Step-by-step explanation:
The windward sails, also known as lateen sails, were found in China and used for advanced maritime expeditions during the Ming Dynasty. The impressive treasure ships built at the shipyard near Nanking were part of a massive fleet commanded by Admiral Zheng He. His first expedition departed in 1405, marking the start of an era of unprecedented seafaring and navigational exploration for China. This fleet included large treasure ships 400 feet in length, boasting multiple masts that carried rattan sails.
The technology and innovative naval designs, including the sternpost rudder and the magnetic compass, gave these vessels the capability to embark on long-distance voyages. Notably, Zheng He's expeditions reached as far as East Africa and the Persian Gulf, and the ships transported a variety of exotic goods and even diplomats back to China. However, this era of exploration came to an end in 1433 when the Ming government halted the naval programs, partly due to changing political and economic priorities.