WHEN Rob Hewitt’s dive boat left without him, he figured it wouldn’t be long before help arrived.

Stuck miles off the coast of Wellington, the experienced New Zealand navy diver was forced to tread water as he waited and waited.

But it wasn’t until the sun set on the horizon hours later that he knew he was really in trouble and facing the biggest fight for his life.

The then 38-year-old had been diving with a team of others when he became stuck in a rip and was carried away from the boat in February 2006.

When he emerged he could see the boat in the distance and assumed it would come back.

But it never found him.

He spent the next four days at sea treading water and staring death in the face.

“I realised people who scaled Mt Everest knew Sir Edmund Hillary had survived before them, but no-one had survived this,” he said of his experience of being stuck at sea.

The father-of-four reveals what went through his mind during that time and how he battled against all the elements to live.

Mr Hewitt said at first he almost refused to believe he’d be left for too long but as the hours turned into days, his survival instinct kicked in.

media_camera The diver made his peace with the sea months later.

“A spirituality came over me,” he told news.com.au from his home in Palmerston North on the North Island of New Zealand.

“I realised I was in massive trouble and began praying.

“Once that sun went down I had the mindset of just surviving.”

As the hours passed and he became more tired he developed a routine for getting rest with the aid of his flotation device and oxygen tank and cried out his wife and children’s names every hour.

He imagined the worst pain he had been through and compared it to the pain he felt at the time, thinking it couldn’t get worse.

The now weakened diver even contemplated dumping his equipment but feared he wouldn’t make the swim back to shore against a strong current.

media_camera Mr Hewitt pictured during his rescue.

He said dying from loneliness scared him more than anything else, and he wanted his family to know that he loved them.

“I knew I was staring death in the face so wanted to stay as alert as possible so when the time came I could say I wasn’t ready yet,” he said.

When he was finally found four days later, he had drifted 36 nautical miles, but the current had swept him 35 miles back near the spot where he vanished.

He was suffering hallucinations and severe hypothermia but was miraculously alive.

He said he thought he was “bigger than Ben Hur” until that fateful day. It took him 12 months, but he has made friends again with the sea by diving back in.

Insight Survival - Richard Prof Richard Bryant on how the body responds in a crisis. Catch the full episode on Tuesday, June 24 at 8:30pm on SBS ONE.

His incredible story features on SBS Insight tonight which asks what it takes to survive.

The show also hears from world expert in the psychological response to trauma, Prof Richard Bryant who said the human body was designed to fight for survival.

Prof Bryant said Mr Hewitt’s case was an exceptional one and his survival chances were increased by his years of navy training.

But he told news.com.au that humans were a species that have worked out ways to survive and that evolution had provided us with an in-built fight or flight response.

He said people under severe stress released adrenalin which created all the body’s reactions that were needed to deal with the threat.

Prof Bryant said while fast-acting defences such as increased heart rate and sweating helped our body fight, survivors also developed slow acting techniques.

These helped calm the body down, allowing us to think more clearly and make better decisions.

Insight Survival - Fiona Fiona Wilde speaks about the moment she realised she was being kidnapped. Catch the full episode on Tuesday, June 24 at 8:30pm on SBS ONE.

The show also features northern NSW woman Fiona Wilde who was held hostage for 30 hours after being taken hostage in the Amazon.

Ms Wilde was on a tour boat which was stopped in the middle of the Amazon River in 2012.

At first she thought it was a robbery, but “once they got us off that boat and got us to run at gun point, that was when I figured this might be real.”

She said she knew she had to stay valuable to the bandits because the “only way out is relying on these three people that have just kidnapped me and are threatening my life.”

Sydney man David Jacobs also appears on the show revealing how he survived the 2008 Mumbai terror attacks.

Insight Survival - David Insight guest David Jacobs rang his wife to say goodbye as he took refuge in his hotel room during a terrorist attack. Catch the full episode on Tuesday, June 24 at 8:30pm on SBS ONE.

Mr Jacobs said he took refuge in a cupboard in his room in the Oberoi Hotel.

While terrorists took over the hotel for three days, his only lifeline was his mobile phone, which he used to stay in touch with friends, family and security analysts who talked him through the siege.

Fellow Sydney man James Dorney also knows what it’s like to live through a terror attack.

He was sitting at his desk on the 92nd floor of the South Tower of the World Trade Center on September 11, 2001, when he saw a massive explosion in the building opposite.

He ignored announcements that his Tower was secure, and started to evacuate.

“It’s impossible to describe a Boeing 767 slamming into the side of the building you’re standing in’. Hundreds of people flooded the stairwells, which he tells the show is “extremely challenging, the feeling of helplessness … Not being able to move”.

Insight Survival - James James Dorney was on the 92nd floor of the World Trade Center’s South Tower on September 11. Catch the full episode on Tuesday, June 24 at 8:30pm on SBS ONE.

What does it take to survive airs on Insight tonight at 8.30pm on SBS ONE.

Originally published as ‘No one has ever survived this’