The prosperity of Indus Valley civilization depended, to a large extent, on its trade and transport. Raw materials were brought by land and water routes from within and outside the valley. They used bullock carts as well as boats for trading purpose.
Boats were probably small, flat-bottomed crafts, perhaps driven by sails.
From the distribution of Indus Valley civilization’s remains, we can assume that they had trade relations with the coastal regions of Persia, and Mesopotamia. Evidences show that trade contacts extended even to Crete and possibly to Egypt.
There was an extensive maritime trade network operating between the Harappan and Mesopotamian civilizations. Such long-distance sea trade became feasible with the development of plank-built watercraft, equipped with a single central mast supporting a sail of woven rushes or cloth.