Mainak was a mountain under the sea.

Mainak is mentioned in the Ramayan.

According to Indian mythology, formerly mountains had wings and could fly like birds, but later on Indra clipped them of their wings by his thunderbolt and since then they became stationary.

Mainak, however, who was able to accelerate his speed with the help of the wind-god, rushed into the ocean and hid himself under its waters. The deity presiding over the ocean, who had been begotten by king Sagar, and was thus an ancestor of Lord Ram, took the opportunity to oblige Sri Ram in search of Sita.

He directed Mainak to come out of his hiding-place and give rest to His envoy Hanuman in the mid-ocean so as to enable him to cross the ocean by easy stages. Out of gratitude to the ocean, who had afforded him shelter all the time, and in order to repay his obligation to the wind-god, Mainak emerged from his asylum and served as a stepping-stone for Hanuman to rest on and replenish his store of energy. Hanuman, however, who was spurred on by his devotion to Sri Ram and depended on His all-sufficient grace, needed no other support and took leave of the mountain by merely acknowledging his services.