Australia's new Antarctic icebreaker floats and it doesn't leak.

The Nuyina will be able to handle: Waves up to sea state nine (14 metres plus significant wave height)

Waves up to sea state nine (14 metres plus significant wave height) Wind speed up to Beaufort 12 (hurricane)

Wind speed up to Beaufort 12 (hurricane) Air temperature ranging from minus 30 degrees Celsius to 45C, and water temperatures ranging from minus 2C to 32C Source: Australian Antarctic Division

Named Nuyina by schoolchildren as part of a competition, the ship is being constructed in Romania and has been put into water for the first time.

The operation took two days and involved pumping 50 Olympic sized swimming pools worth of water from the Danube River into its dry dock, raising the water level by six metres.

The Australian Antarctic Division's Modernisation Program Manager, Rob Bryson, said he was pleased the floating of the ship went to plan.

"We've been testing it over the last five days to make sure there was no water ingress into the ship and I can safely and happily report there was no water ingress," he said.

Buoyancy bags at the stern of Nuyina help keep the bow and stern level during the floating tests in Romania. ( Supplied: Michiel Jordaan/Australian Antarctic Division )

The ship currently weighs 10,000 tonnes but will be 25,000 tonnes once completed and fully loaded.

Now the ship has been moved to a wet dock construction of the upper levels will begin.

"There's another six decks to go on, that includes all the accommodation areas, all the scientific laboratories, the bridge of the ship and the upper masts and all that kind of good stuff," Mr Bryson said.

The Nuyina will have a crew of 32, with 117 passengers. ( Supplied: Damen/Australian Antarctic Division )

By late next year, the ship's icebreaking capabilities will be tested.

"We'll be taking the ship up into the Arctic and testing its icebreaking abilities off Norway in the sea ice up there," he said.

The $2 billion ship is due to replace the Aurora Australis by 2020 and is expected to have a 30-year working life.