The tragic story behind Ken's marathon desert bike...

FOR 40 years, Ken McIlwain, from Ballina, kept a secret.

But the Ballina man is now letting the world know he is a victim of sexual abuse when he was aged in his late teens in the hope it will help other survivors on their healing journey.

He last Saturday also left on a 48-day solo bicycle ride around the central deserts, covering a total of 3053km, on his second marathon cycle to raise money and awareness of the work of Bravehearts, which supports abuse victims and aims to protect children.

Ken's abuse, tragically, happened after he signed up to serve the country as an apprentice in the Royal Australian Navy.

From the age of 16, he endured abuse from senior staff of the training establishment where has was initially posted.

He reported the abuse, but he couldn't get anyone to believe me, and eventually was discharged from the navy.

Scarred with that felling of not being believed, he didn't tell a sole about his abuse until 2011 after watching a television report on the Skype sexual assault at the Australian Defence Force Academy in Canberra.

"I went off the tree a bit that night," Ken, now aged 64, said.

"I went to my room and saw my GP that morning, and from there I've got help.

"From 2011 right up until this very day, I see a psychologist every month and a psychiatrist every six months.

"I tell other victims or survivors, don't try and fight it yourself.

"And don't give up."

Ken said he considered himself somewhat lucky as his method of finding peace was not through drugs or alcohol, but through running.

"Running is my relief," he said.

"And that's why I do this stuff (marathon bike rides) -- it gets rid of my demons and makes me see the world in a better view.

"Out in the outback, that provides some solace."

Ken did receive an apology from the navy.

But even now, he said he still has moments where he thinks people still don't believe his story.

"That's where a lot of victims and survivors have a problem, with people believing them," he said.

"It's a terrible feeling inside, that no on believes you."

As Ken cycles from Alice Springs return via Boulia, Birdsville, Marree, Oodnadatta and Finke, he has a physical reminder that his abuse is over.

For years he carried a piece of paper, then a photograph of that paper on his phone, with the words: "A different time, a different place. I'm safe now."

He know has that tattooed on his left forearm.

Ken has been planning his latest marathon ride for two years.

All up, he will carry about 50kg on his bike and in a trailer, including water. He also carries the necessary emergency equipment.

He said it was very important to him now to be sharing his story.

"If I can save one or two kids, that's really good. I feel good about that," he said.

You can follow Ken's journey, and donate to Bravehearts through the website kennymac adventures.com.au.