Marine scientists heading out on a month-long voyage to explore for the first time the deep waters off Australia's east coast, estimate that up to half of all animals they encounter will be new species or, at least, ones never seen in Australian waters.

Led by Museums Victoria, the international team of researchers will sample and film the cold, dark abyss that begins where Australia's continental shelf ends.

It's an unknown world, largely populated by creatures science is yet to meet.

The pioneering expedition left Launceston on Monday. Over the coming month the 40 scientists on board will sample fish, sea stars, crabs and worms from up to four kilometres beneath the surface.

The team, made up of researchers from 14 institutions and seven countries, will also map the marine seascape for the first time including deep-sea valleys, undersea volcanoes and silty plateaus.

"No one has surveyed these areas, which is pretty weird because sometimes we're only going to be 100 kilometres off the coast," said Museums Victoria's Tim O'Hara, the chief scientist on the "Sampling the Abyss" mission.

Among the larger creatures to call the depths home is Sloane's viperfish, which holds the world record for largest teeth relative to head size in a fish.

Like many other deep-sea creatures, it's not what you would call classically good looking. But these are clever creatures, which have evolved over 40 million years to survive in harsh conditions where temperatures hover around 4-5 degrees and life is lived in almost complete darkness.

Another creature of the deep the anglerfish, for example, has evolved to create its own light source using bioluminescence.

Found a kilometre below the surface, the anglerfish uses the light which dangles from an antennae to attract prey. The light hovers just above its mouth.

Researchers will use remote-controlled video cameras to gather footage and dredges to take samples. However a lot of the life lurking in the dark depths will be invisible to the naked eye.

"But they look amazing when you put them under the microscope," Dr O'Hara said. "They're all fangs and spines and blobs of jelly."

Two thirds of the planet is ocean and of that, the majority is deep ocean. Abyss refers to waters deeper than 3.5 kilometres deep.

"At that depth, anything with any air in it at all would be completely crushed, including humans," Dr O'Hara said.

Fifty-nine research and support staff will live on CSIRO's research vessel, the RV Investigator.

"It's no tinnie," Dr O'Hara said of the $126 million ship. "It's about 100 metres long and nine storeys high."

However it will be a dry ship as it travels the 3200 kilometres from Tasmania to Fraser Island before docking in Brisbane on June 16.