Both Australia and Japan have filed their detailed written arguments to the court and the case has been set down for oral hearing in The Hague.
The Australia government anticipates the case is likely to be listed for hearing in the latter half of next year.
Attorney-General Nicola Roxon said the decision to start legal proceedings was not taken lightly.
"The Australian government considers Japan's whaling program is contrary to its international obligations and should stop," said Ms Roxon.
Citing the Fisheries Agency, Kyodo News reported on Friday three vessels had left from the far-western port of Shimonoseki, while environmental group Greenpeace said the mother ship had left another port also in the country's west.
The fleet plans to hunt up to 935 Antarctic minke whales and up to 50 fin whales through March, the fisheries agency said earlier.
Greens Acting Leader Adam Bandt called on the Australian government to seek a court injunction to stop the whaling.
"The Labor government and the coalition government before its attempts to stop this illegal whaling have been an abject failure because they've been half-hearted," he told reporters in Melbourne.
"The government says it wants to do something about it and has commenced proceedings in the court, but it hasn't done the simple thing that would actually stop the whaling, and that is go off and seek an injunction.
"If the Japanese government can go off to a United States court and get an injunction to stop the Sea Shepherd, well then the Australian government can go off as well and get an injunction to stop this illegal whaling."
- AAP
