This map is part of a series of 16 animated maps showing the history of The Age of Discovery.
Navigational conditions in the Indian Ocean were relatively favourable and familiar to Arab sailors as far back as Antiquity.
From May to October, the winds blow from the southeast and turn towards India, near the Equator. Whereas, for the other six months of the year, the dominant winds blow in the opposite direction.
By taking advantage of the prevailing winds during each period, sailors could take the same route in both directions.
A similar system of alternating seasons is also found in the Malay Archipelago.
Once past the Philippines and heading north along the coast of China and Japan, the presence of typhoons made navigation more difficult.
In the 15th century, trade in the Indian Ocean linked southern ports on the Arab peninsula with Islamic trading posts on the African coast and those on the Indian coast: Surat in the north, Goa in the centre and Calicut to the south.
This triangle of trading posts around the Indian Ocean was dominated by Muslim merchants.
As commercial ships travelled further to the west via Sri Lanka and the Bay of Bengal, they created a link with Malacca, itself part of a vast trading network that stretched from Japan and China to the Spice Islands and Java.
The northern part of this second trading system was in the hands of the Chinese and Japanese, while the southern areas were dominated by the Muslims and Malaysians.
This maritime traffic concentrated on many products, but in particular spices. Pepper, cinnamon, cloves and nutmeg were produced in the Spice Islands, Sumatra and Java, on the Malaysian peninsula, in Sri Lanka and southern India.
The majority of these products was exported to China, via Malacca, or to Europe, via the ports of Ormuz and Aden.
India also exported cotton cloth to trading posts on the African coast.
The ships would come back heavy with gold from Sofala, ivory and slaves.
China exported silks and porcelain.
The Arab world sold horses, weapons and rose water.
And Europe paid with gold and metals.