Mick Fanning of Australia is seen shortly before being attacked by a shark during the finals of the J-Bay Open in Jeffrey's Bay, South Africa, in this July 19, 2015 handout courtesy of World Surf League.  [Photo/Agencies]

"I froze. I saw him start to get manhandled by the shark, and I was kind of freaking out," he said.

"I just started paddling for him, fearing for his life. I came over the wave and I was just hoping he would be there. He was away from the board, the shark bit his leg rope and I went into panic mode.

"I felt like I couldn't get there in time. It was a horrific feeling."

Earlier on Tuesday, Fanning's mother Elizabeth Osborne spoke to the Nine Network, offering a heartfelt thanks to the Wilson family.

"Thank you to your family and especially to Julian for being such a hero and caring about what was happening to my son," Osborne told Wilson's mother.

"We have been friends for quite a while and this will just cement a very, very close friendship."

Osborne said when she witnessed the attack live on television, the thought that she had lost her son crossed her mind.

"I was absolutely terrified. I went over to the television almost as though I could pull him out ... to save him," she said.

While the incident will leave an emotional scar on Fanning for the rest of his career, the 34-year-old vowed to get back on the surfboard, saying surfing is just part of his nature.

"I've been surfing for 30 years, and yeah (all surfers have) seen (sharks) from a distance. But it's like crossing the road, you never know if you'll get hit," he said.

"I am sure I will surf again, surfing has given me so much." he said.