Greenpeace activists back on Rainbow Warrior ship

GREENPEACE protestors who boarded a South Korea-bound coal ship on Wednesday morning are now back on the group's Rainbow Warrior, en route to Cairns.

The six activists scrambled aboard the MV Meister, a fully-laden vessel hauling coal for its Korean owner Samsun-Logix in the Coral Sea, beyond the Great Barrier Reef.

The surprised Korean crew were given orders by owners to continue their journey as planned and left the protestors to their own devices.

The six protesters handed the Korean captain a letter explaining their actions, but the captain did not have a strong understanding of English.

After 28 hours, the team were picked up by the same small boat that first delivered them to the Meister.

Greenpeace Australia senior climate campaigner Georgina Woods described the six as courageous in their struggle against the coal industry.

"They had a rough, long night because the seas are quite big out here," Ms Woods said.

"We brought them back to the Warrior so we could go together to Cairns to talk to Australia about why we did what we did."

The action, she said, was part of a larger push for a "campaign of civil disobedience" against the coal industry.

Queensland Resources Council chief Michael Roche - who heads the peak body for mine companies - called the boarding "pointless and potentially dangerous".

"Queensland's largest export industry did not skip a beat, continuing the economic activity that most people acknowledge carried the country through the Global Financial Crisis," Mr Roche said.

He said he hoped the Rainbow Warrior 3 crew had enjoyed its month-long holiday voyage along the Australian east coast.

Police and other authorities are now investigating whether to press charges against those who boarded the Meister.

The Rainbow Warrior is scheduled to arrive in Cairns within two days.