Shackleton Epic expedition crew onboard the Alexandra Shackleton in Admiralty Bay.

Shackleton Epic expedition crew onboard the Alexandra Shackleton in Admiralty Bay. Photo: Paul Larsen

MOVING their thin boat through icy seas, six British and Australian adventurers are setting out to recreate one of humankind's great escapes.

British explorer Ernest Shackleton set out to cross Antarctica in 1914. When his ship became jammed in ice, he and his crew clambered in a seven-metre lifeboat and navigated 1500 kilometres through the world's most perilous ocean to safety.

On Tuesday night, British-Australian Tim Jarvis and his crew will sail for Elephant Island, where they will begin retracing Shackleton's journey in an exact replica of his boat.

Sir Ernest Henry Shackleton and two members of his expedition team beside a Union Jack within 111 miles of the South Pole, a record feat in 1909.  Photo by Getty Images Click for more photos

Shackleton's Antarctic adventures

Sir Ernest Henry Shackleton and two members of his expedition team beside a Union Jack within 111 miles of the South Pole, a record feat in 1909. Photo by Getty Images

''She has no keel, she's not very big and she's not really very seaworthy,'' Mr Jarvis said.

After sailing from Argentina at the start of January, the crew has spent the past fortnight on a Polish base off the Antarctic peninsula, trialling their boat and drinking vodka while they wait for rough seas to drop.

''The mast goes from touching the water on one side to touching the other,'' he said. ''There's a lot of sea ice down here this year. Framed against the glaciers in the background [the boat] looks completely insubstantial.''

Four of the crew will sit below deck and two on top, none with room to stretch out. ''It's like being in a space capsule,'' he said. But that will provide some balance for their two weeks on wind-whipped seas. Polar adventurers typically rely on constant movement to stave off freezing. But they will rely on sugary tea, animal fat and hugging each other for warmth. They will have to use sextants to navigate the ice that originally brought Shackleton undone. Veering away from due north could spell the end of the expedition.

''Our boat has no capacity at all to push through anything other than water,'' he said.

The expedition will travel with reserve emergency equipment and a support vessel will trail about 20 nautical miles behind.

Landing on the island will be dangerous , Mr Jarvis said. ''If we reach it at night in a storm, that's a very dangerous situation to be in,'' he said.

After landing, Mr Jarvis and two of his crew will traverse the island's mountain range.

Mr Jarvis recites the dangers of his journey with the air of a man who has spent years planning for its risks. But that hasn't inured him from the awe of being there.

''It's grey here; it's grey and cold; it's a very very inhospitable place,'' he said.

''You're just this tiny little speck in this tumultuous grey ocean. You have every right to be scared.''