Friends and foes in the ocean

Hanuman who had the unique ability of changing his size, assumed a huge form, and with arms outstretched took a leap from the mount of Mahendra and flew over the ocean towards Lanka.

A brief translation from the Raamayana, describes the event...

Thinking that he was Garuda himself the great Hanuman jumped up with great force. Because of the speed of his course, the trees on the mountain were pulled up with their roots. With the flowering trees rushing along with him Hanuman entered the skies. The trees went with him some distance and it seemed as though they were well-wishers who went with him some distance to make the journey fruitful.

As he was flying, a mountain emerged from the depths of the ocean. Hanuman considering it an obstacle was about to fly over it, when the mountain requested Hanuman to rest a bit. This hitherto submerged mountain was Mainaka, an old friend of Vayu. Hanuman needed no rest but in order to respect the wishes of Mainaka, touched it momentarily as he continued his flight. Surasa was the mother of Naagas and one of the wives of rishi Kashyapa.

Surasa was the mother of Naagas and one of the wives of rishi Kashyapa. She was assigned the task of testing Hanuman’s strength (bala) and intelligence (buddhi).

Assuming a terrifying form she accosted Hanuman and told him that she had a boon whereby no living being could pass by her without entering her mouth.

Hanuman agreeing to the proposal began to grow immensely. As Surasa widened her mouth further and further to accommodate the increasing form of Hanuman; in the blink of an eye, Hanuman became tiny and quickly flew in and out of her gaping mouth. As he took his leave he prostrated to her addressing her as “Daakshayani”. Simhika a demoness, sometimes identified as the sister of Hiranyaaksha and Hiranyakashipu had been granted a boon that she could wield power over shadows. Thus she drew the shadow cast by the flying Hanuman and pulled him towards her. Hanuman allowed himself to be swallowed up by her. Once inside her body, he increased in size and emerged outside by tearing open her body and thus killing her.

Lankini* was a powerful demoness ordered to guard the city of Lanka. When Hanuman set foot in Lanka, assuming a tiny form in order to be inconspicuous, he came across Lankini. Lankini tried to prevent Hanuman from entering the city but she was overpowered by him. Surprised at the power of Hanuman, she suddenly recalled the prophecy of the destruction of Raavana and his demons when she would be defeated by a monkey. Lankini, who was bound by a curse to guard the city of demons, welcomed Hanuman and wished him success.

*does not find mention in Valmiki Raamayana

Thus with single minded devotion and strength of purpose did Hanuman overcome the various impediments and successfully meet Sita in AshokaVaatika.