It’s minus 23 degrees Celsius, dark and you’re standing on the edge of a hole dug into the sea-ice — what do you do?

If you’re an Australian Antarctic Program expeditioner you plunge in of course!

Davis research Station Leader, Simon Goninon, said expeditioners look forward to the midwinter swim with a mixture of excitement, trepidation and dread.

“When it’s below minus 23 degrees on the ice, and about minus 1.5 degrees in the water, and you strip down to your budgie smugglers, believe me you know you’re alive,” Mr Goninon said.

“It’s one of those things, you know it might sting a bit but it’s an occasion you’ll remember forever.”

To mark the shortest day of the year, expeditioners at Australia’s three Antarctic research stations and on sub Antarctic Macquarie Island take an icy dip.

The astronomical winter solstice is on 22 June at 1:54am, when the South Pole is tilted furthest from the sun.

Midwinter marks a significant milestone for the wintering expeditioners, who spend between 12–18 months on the icy continent.

“This is a turning point for our team and it also means the sun will soon return to the continent after weeks of living in twilight, when the sun has just been skimming below the horizon,” he said.

“The midwinter celebrations will include a magnificent feast, exchange of handmade gifts, home-grown entertainment and messages from home.”

On Macquarie Island the expeditioners do two swims, dashing across the narrow Isthmus to swim in the cold waters of both the west and east coast.

This winter there are 74 people at Australia’s stations, with most due to return home at the end of the year.

The Governor-General, His Excellency General the Honourable Sir Peter Cosgrove AK MC (Retd) and Minister for the Environment Sussan Ley MP sent video greetings to the expeditioners for their midwinter celebrations.