MAGNETIC COMPASS CALLED MATSYA YANTRA WAS FIRST USED BY HINDUS

The magnetic compass was first used in India around 1800 BCE, for navigational purposes at sea, and was known as ‘Matsya yantra’ (which roughly translates to fish machine), because of the placement of a metallic piece shaped into a fish in a cup of oil .

The work “Merchants Treasure” written at Cairo by Baylak al Kiljaki mentions the magnetic needle as being in use in the Indian Ocean.
The route that Fa-hien , the celebrated Chinese monk, took to return home after his stay in India (412-413) is fully described by him. Leaving Tramralipti, the Orissa port, he took fourteen days to reach Sri Lanka. From there he embarked for Java and called at Nicobars (Nakka-varam), the island of the naked. From Nicobar the ship passed through the Straits of Malacca into the Pacific. Oceanic travel was therefore well advanced in the fifth century and Indian mariners not merely crossed the Bay of Bengal at its widest point, but sailed far out into the Pacific