Vaivaswat Manu was a rishi who was also the son of Vivaswan, the sun god. He was equal to his father and grandfather Brahma in terms of power, glory, strength and austerities performed. He practised tremendous penance in the forest of Badari for ten thousand years. One day, while he was engaged in ascetic practices, a fish approached him on the banks of river Chirini and addressed him thus, "Oh respectful rishi, I am a little fish residing here in this river and I am afraid that big fishes will swallow me. Because the large fishes always live upon small fishes, my life is in constant danger. Therefore do protect me from such an eventuality. Kindly take me with you and keep me in a place where I am safe from predators. This act will earn you merits.
The rishi was taken by compassion for the little fish and took it to his home after taking it out from water. He then put it back in an earthen water vessel and reared it carefully. The fish began to grow in size in that vessel and atlast one day it could no longer remain inside that earthen pot. It therefore entreated Manu to take it out and place it in a larger body of water. Accordingly Manu took the fish out of the vessel and carried it to a large tank and put it in the water of the tank. After many years the fish grew up there as well and the space in the tank was inadequate for it even though the tank was big enough. The fish then requested Manu to take it to Ganga where it can play around with much more ease. Manu complied with its wish and placed it in Ganga. There the fish played around for a long time and then one day it became so big that even Ganga could not hold it and therefore it requested Manu to put it in the ocean. Manu then took out the fish to the sea and put it there with ease, despite the great bulk. When it was being pushed to the ocean it told Manu smilingly, "You have taken care of me most lovingly and therefore I would pay back your debt. Listen to me carefully. The pralaya or universal destruction is going to take place for ending this period of creation. Therefore the entire universe will be dissolved and will be recreated. All the mobile and immobile creatures will perish. Since you have so faithfully served me, I shall save you. A huge flood is coming that will engulf the entire earth. You must build a huge boat which will be strong enough to carry you and the other seven pious rishis, and all the seeds and preserve them carefully. The boat shall be tied to a strong rope. Then wait for me. I shall appear before you having a horn on my nose and you can thus recognize me. Thus said the fish disappeared and Manu accordingly built a strong boat, procured the different seeds and set sail on a surging sea. Then he thought of the fish and the fish appeared before him with a horn on his nose and Manu tied the boat with the rope to that horn. The sea got even more furious and the entire universe was flooded with water. But the fish moved with ease on that roaring and extremely turbulent sea. Many and his companions had no difficulty at all. There was no land to be seen anywhere. Everywhere there was water. The fish diligently carried Manu and his boat over that ocean for many days and then they could see in the horizon the mighty peak of the Himalayas. The fish directed itself towards that peak and helped them tie the boat to that peak. The peak therefore became known as Nauvandhana or the harbour. The fish then addressed the rishis saying that it was Brahma, the Lord of all creatures who assumed the form of a fish to save the rishis from the great flood. He also entrusted Manu to create again all beings by acquiring the power of creation through severe austerities. Vaivaswat Manu therefore set on the task of creating all beings again and the period thereafter came to be known after him as Vaivaswat Manvantara. One Manvantara consists of 71 cycles of four Yugas and in one Kalpa or a day of Brahma there are 14 such Manvantaras. The present Manvantara is Vaivaswat Manvantara after Manu and it is the seventh Manvantara in present Kalpa according to Puranas. Some Puranas also depict the fish to be the first avatara or incarnation of Lord Vishnu.
