Sydney (AFP) - A man who jumped off San Francisco's Golden Gate Bridge to try to take his own life and was kept afloat by a sea lion said Wednesday suicide prevention was now his life's work.

Kevin Hines, in Australia to speak at several conferences, was a teenager struggling with mental illness and depression when he jumped off the famous bridge in 2000.

He survived the fall, only to see what he thought was a shark beneath him.

"I was freaking out in those waters. And I was thinking I didn't die there and now I am going to die here in the water because of a creature of some sort," he told AFP.

"I really thought it was a shark and I thought it was going to take off a leg and I was panicking.

"And then it just didn't, it just kept circling beneath me. I remember floating atop the water and this thing just bumping me, bumping me up."

Hines later spoke to a man who had been on the bridge that day and who had seen that it was not a shark but a sea lion.

"Everyone who looked down saw this creature circling in a clockwise motion beneath me. So they saw me laying atop the water and being bumped.

"This thing beneath me didn't stop or didn't go away until I heard the boat behind me."

Hines believes another factor also helped save his life -- a woman driving past saw his plunge and immediately reported it to a friend in the coastguard.

He said without her call, the coastguard would not have known his exact location and would not have got to him before hypothermia or his injuries, including serious back problems, caused him to drown.

"I'm one of less than one percent to have survived that fall," he acknowledged. Many of the survivors never regain full mobility, as he has.

"I've been given the gift of a second chance of life so many times," he said.

Hines, now 33, is a mental health advocate who speaks at events around the world in a bid to prevent suicides.

"This is absolutely my life's passion and my life's work," he said.

"What really I'm talking about here, it crosses all boundaries... every race, creed, colour. Everyone is touched by this somehow, some way... suicide prevention is everyone's business."