A polar explorer who famously retraced Douglas Mawson's Antarctic trek launched an ambitious new challenge Sunday -- recreating Ernest Shackleton's perilous crossing of the Southern Ocean.

Tim Jarvis, a renowned British/Australian adventurer who in 2007 re-enacted Mawson's 1912 odyssey across the frozen continent, is planning a similar trip in 2013 to follow Shackleton's dramatic 1916 voyage.

Jarvis described the perilous 800 nautical mile (1,300 kilometre) Southern Ocean crossing in a spartan lifeboat and punishing traverse of South Georgia Island with very basic gear and rations as "the biggest survival journey of them all".

Shackleton had hoped to complete the first land crossing of the Antarctic when his ship, the Endurance, was crushed by ice, triggering a desperate mission on a lifeboat from nearby Elephant Island to South Georgia for help.

The adventurer and five other men made it across the hostile ocean with little more than the clothes on their backs and the most basic of rations and battled across the rugged island to a whaling station to raise the alarm.

It was a two-year ordeal that "well and truly bookmarked the end of the heroic era of exploration that started in 1895 when the first person set foot on the Antarctic and finished with the First World War", Jarvis said.

Inspired by the story and hoping to map the dramatic changes that global warming has brought to the region, Jarvis and a crew of five sailors will repeat the ocean crossing in a replica boat with all the same privations.

They will be without navigational aids or any modern equipment, live off the same lard rations as Shackleton's men and wear the same clothes as they battle high seas and icy, bleak conditions to reach Stromness on South Georgia.

"I'm expecting constant hardship and vigilance; there are periods of darkness down there, we're on a boat with absolutely no modern navigational aids whatsoever, we'll just be going into darkness," Jarvis told AFP at the crew's official farewell from Sydney on Sunday.

"Icebergs can loom up on the horizon, we wouldn't even see them until they're on us, there are whales, it's big, big sea," he added.

"It's a very, very challenging boat journey and we'll require the luck that he had I think. Expect the worst, hope for the best."

Along with Norway's Roald Amundsen, the first man to reach the South Pole in 1911, Australian explorer Mawson and Briton Robert Falcon Scott -- his patron-turned-rival -- Shackleton was among the great Antarctic explorers.

Though his first polar expedition was with Scott in 1901, Shackleton and his mentor went on to part ways, sparking an intense rivalry that overshadowed his career. Scott perished on his return journey from the pole in 1912, having been beaten to the milestone by Amundsen five weeks earlier.

Shackleton died of a heart attack off South Georgia in 1922 during his fourth Antarctic expedition, aiming to circumnavigate the continent.

He is buried on the island and Jarvis said it would be "be fantastic to feel that he was there with us", almost 100 years on from his original mercy dash.

The men will set off in their replica lifeboat, named the Alexandra Shackleton after the explorer's granddaughter, in early January 2013 from South America and expect the journey to take two months.

It has taken six years and Aus$2.5 million (US$2.6 million) to plan.

The sailors are currently undertaking basic mountaineering training in the French Alps "testing gear and learning how to pull themselves out of crevasses with virtually no equipment -- we've only got a tiny section of rope".

A support vessel, the Australis, a modern and fully equipped steel-hulled motor boat will trail the lifeboat, but will only go to its aid in the event of a serious emergency.

As well as honouring Shackleton's legacy, Jarvis hopes to raise awareness about the impact of climate change on the polar regions.

"The irony is that Shackleton tried to save his men from Antarctica," he said. "We are now trying to save Antarctica from man."