Indian maritime history begins during the 3rd millennium BCE, when the Indus Valley Civilisation initiated maritime trading contact with Mesopotamia. India's long coastline, with the Deccan Peninsula projecting into the Indian Ocean, helped foster extensive maritime trade and cultural exchange. The Indian Ocean is named after India due to its prominent geographic position in the region.
As per Vedic records, Indian traders and merchants traded with the Far East and Arabia. During the Maurya Empire (c. 320–185 BCE), there was a definite "naval department" to supervise the ships and trade.At the end of 1st century BCE, Indian products reached the Romans during the rule of Augustus, and the Roman historian Strabo mentions an increase in Roman trade with India following the Roman annexation of Egypt. As trade between India and the Greco-Roman world increased, spices became the main import from India to the Western world, bypassing silk and other commodities. Indians were present in Alexandria, while Christian and Jewish settlers from Rome continued to live in India long after the fall of the Roman Empire, which resulted in Rome's loss of the Red Sea ports, previously used to secure trade with India by the Greco-Roman world since the Ptolemaic dynasty. The Indian commercial connection with Southeast Asia proved vital to the merchants of Arabia and Persia during the 7th–8th century. A study published in 2013 found that some 11 percent of Australian Aboriginal DNA is of Indian origin and suggests these immigrants arrived about 4,000 years ago, possibly at the same time dingoes first arrived in Australia.
On orders of Manuel I of Portugal, four vessels under the command of navigator Vasco da Gama rounded the Cape of Good Hope, continuing to the eastern coast of Africa to Malindi to sail across the Indian Ocean to Calicut by 1498. This discovery of the Cape Route meant that the wealth of the Indies was now open for the Europeans to explore. The Portuguese Empire was the first European empire to grow from spice trade. By 1869, the completion of the Suez Canal resulted in a faster maritime route between Europe and India, allowing the United Kingdom to more easily maintain control in India and the Indian Ocean.
5 April is celebrated as National Maritime Day in India. On this day in 1919, navigation history was created when SS Loyalty, the first ship of the Scindia Steam Navigation Company Ltd., journeyed to the United Kingdom, a crucial step for India's shipping history when sea routes were controlled by the British.
The region around the Indus River began to show visible increase in both the length and the frequency of maritime voyages by 3000 BCE. Optimum conditions for viable long-distance voyages existed in this region by 2900 BCE. Mesopotamian inscriptions indicate that Indian traders from the Indus Valley—carrying copper, hardwoods, ivory, pearls, carnelian, and gold—were active in Mesopotamia during the reign of Sargon of Akkad (c. 2300 BCE). Gosch & Stearns write on the Indus Valley's pre-modern maritime travel: Evidence exists that Harappans were bulk-shipping timber and special woods to Sumer on ships and luxury items such as lapis lazuli. The trade in lapis lazuli was carried out from northern Afghanistan over eastern Iran to Sumer but during the Mature Harappan period an Indus colony was established at Shortugai in Central Asia near the Badakshan mines and the lapis stones were brought overland to Lothal in Gujarat and shipped to Oman, Bahrain and Mesopotamia.
Archaeological research at sites in Mesopotamia, Bahrain, and Oman has led to the recovery of artefacts traceable to the Indus Valley civilisation, confirming the information on the inscriptions. Among the most important of these objects are stamp seals carved in soapstone, stone weights, and colourful carnelian beads....Most of the trade between Mesopotamia and the Indus Valley was indirect. Shippers from both regions converged in Persian Gulf ports, especially on the island of Bahrain (known as Dilmun to the Sumerians). Numerous small Indus-style artefacts have been recovered at locations on Bahrain and further down the coast of the Arabian Peninsula in Oman. Stamp seals produced in Bahrain have been found at sites in Mesopotamia and the Indus Valley, strengthening the likelihood that the island may have acted as a redistribution point for goods coming from Mesopotamia and the Indus area....There are hints from the digs at Ur, a major Sumerian city-state on the Euphrates, that some Indus Valley merchants and artisans (bead makers) may have established communities in Mesopotamia.
The world's first dock at Lothal (2400 BCE) was located away from the main current to avoid deposition of silt. Modern oceanographers have observed that the Harappans must have possessed great knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering. This was the earliest known dock found in the world, equipped to berth and service ships. It is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. This knowledge also enabled them to select Lothal's location in the first place, as the Gulf of Khambhat has the highest tidal amplitude and ships can be sluiced through flow tides in the river estuary. The engineers built a trapezoidal structure, with north–south arms of average 21.8 metres (71.5 ft), and east–west arms of 37 metres (121 ft).
Excavations at Golbai Sasan in Odisha have shown a Neolithic culture dating to as early as ca. 2300 BC, followed by a Chalcolithic (copper age) culture and then an Iron Age culture starting around 900 BC. Tools found at this site indicate boat building, perhaps for coastal trade. Fish bones, fishing hooks, barbed spears and harpoons show that fishing was an important part of the economy. Some artefacts of the Chalcolithic period are similar to artefacts found in Vietnam, indicating possible contact with Indochina at a very early period.
Indians had already been trading with Egypt for a long time even before the conquest of Egypt by the Romans. At the end of 1st century BCE Indian products reached the Romans during the rule of Augustus, and the Roman historian Strabo mentions an increase in Roman trade with India following the Roman annexation of Egypt. Recent excavations at Berenike in Egypt have confirmed, there was a small community of Indian Buddhists at Alexandria, the greatest of all Roman ports. A large number of significant finds have been made providing evidence of the cargo from the Malabar Coast and the presence of Tamil people from South India and Jaffna being at this last outpost of the Roman Empire.
Indian cartography locates the Pole star, and other constellations of use in navigational charts. These charts may have been in use by the beginning of the Common Era for purposes of navigation. Detailed maps of considerable length describing the locations of settlements, sea shores, rivers, and mountains were also made. The Periplus Maris Erythraei mentions a time when sea trade between India and Egypt did not involve direct sailings. The cargo under these situations was shipped to Aden:
Eudaimon Arabia was called fortunate, being once a city, when, because ships neither came from India to Egypt nor did those from Egypt dare to go further but only came as far as this place, it received the cargoes from both, just as Alexandria receives goods brought from outside and from Egypt.
Tamil Pandya embassies were received by Augustus Caesar and Roman historians mention a total of four embassies from the Tamil country. Pliny famously mentions the expenditure of one million sestertii every year on goods such as pepper, fine cloth and gems from the southern coasts of India. He also mentions 10,000 horses shipped to this region each year. Tamil inscriptions have been found in Luxor in Egypt. In turn Tamil literature from the Classical period mentions foreign ships arriving for trade and paying in gold for products.