Boat Swimming In The Sky

Boats were used between 4000 BCE and 3000 BCE in Sumer, ancient Egypt and in the Indian Ocean.
Boats played a very important part in the commerce between the Indus Valley Civilization and Mesopotamia. Evidence of varying models of boats has also been discovered in various Indus Valley sites.
The accounts of historians Herodotus, Pliny the Elder, and Strabo suggest that boats were being used for commerce and traveling.