As a photo of her family huddling in the water beneath a jetty surrounded by flames went viral, Tasmanian mother of five Bonnie Walker braced herself to lose her children and her parents.



The picture of her parents and her five children huddling together and treading water in the only place where the flames could not reach, showed a desperate attempt to survive in hellish conditions.



Walker's family did not die.



They eventually managed to escape in a salvaged dinghy before making it to a hotel outside the fire zone.



Speaking to Australia's ABC network, the family - now reunited - recounted their near unbelievable escape.



"I had a funeral that I had to attend in Hobart on Friday, so it was already a sad day for me." Walker said.



"It was really hot and probably mid-30s by that point."



Walker's five children, aged between 11 and two, stayed in the care of her parents Tim and Tammy Holmes who lived next door to the family home in the small coastal town of Dunalley.



As Walker drove toward Hobart, bush fires tore through the land on either side of her car.



She managed to get through only minutes before flames crossed the road, cutting her off from her family.



"We just waited by the phone and received a message at 3.30pm to say that mum and dad had evacuated, that they were surrounded by fire, and could we pray," Walker said.



"So I braced myself to lose my children and my parents."



And then the photo of her family surfaced in the media.



"It's still quite upsetting to see the image, it's all of my, our, five children underneath the jetty huddled up to neck deep sea water which is cold. We swam the day before and it was cold.



"So I knew that that would be a challenge, to keep three non-swimmers above water. And with only my mum and dad and our eldest daughter."



"My father rallied against all odds and managed to go up and get a little dinghy off the foreshore, loaded our children in and my mum, and then dragged it into a headwind 200 metres or 300m around the point.



"He got them to safety so that they weren't breathing the polluted air."



Grandfather Tim Holmes said oxygen was rapidly running out.



"There was only about probably 200 millimetres to 300mm of air above the water," he said.



"So we were all just heads, water up to our chins just trying to breathe because it was just, the atmosphere was so incredibly toxic."



Holmes got the family to safety at the Dunalley Hotel where they were rescued the next day.



Walker said the relief at having her family back was "indescribable".



"I spent a lot of time with good friends and prayed like I've never prayed before and I think those prayers have been answered."