Mumbai, April 14 (IANS): Prime Minister Narendra Modi on Thursday recalled India's rich maritime heritage, dating back to the world's first dock built at Lothal in Gujarat around 2,500 BC.

"This dock was equipped to berth and service ships. It was built after studying tidal flows," Modi said of Lothal, still known by the same name in Ahmedabad district.

Besides Lothal, there were several other important ancient Indian ports which proved to be major drivers of global maritime trade over 2000 years ago, he said.

These were Barygaza or modern day Bharuch in Gujarat, Muziris of modern Kodungallur near Kochi in Kerala, Kaveripattinam and Korkai or today's Tuticorin, both in Tamil Nadu, and Arikamedu in Ariyankuppam district of Puducherry.

"There are many references in ancient Indian literature, Greek and Roman works about the vibrant maritime trade of India with Rome, Greece, Egypt and Arabia. 

"Ancient and medieval Indian traders maintained links with countries in South-East and East Asia, Africa, Arabia and Europe," Modi said.

He said the chief architect of India's Constitution, B.R. Ambedkar, whose 125th birth anniversary is being celebrated on Thursday, was also the architect of the country's water and river navigation policy.

He said Ambedkar created two powerful institutions -- Central Waterways, Irrigation and Navigation Commission and Central Technical Power Board -- to best utilize water resources and help projects serve purposes other than irrigation.

"Ambedkar emphasized the importance of the new waterways policy in order to lay the foundation for a regime of prosperity for the millions of poor. I am happy to state that we have embarked on the development of National Waterways in keeping with Babasaheb's vision and foresight," Modi said.

Modi pointed out that 70 percent of the earth's surface was covered by water and 97 percent of this (water) was in the oceans.

Oceans also contained 99 percent of the living space on Earth, which meant that our lifestyles, transport systems and trading behavior should not spoil the ocean ecology.

Modi pointed out that the challenges of climate change had shown that even offshore human behaviour can change the ecology of glaciers and oceans.

While maritime transport can be the most extensive and eco-friendly mode, care must be taken on maritime security, freedom of navigation and safety and security of sea lanes, he said.