The departure of tonight's Bass Strait ferry from Tasmania to Melbourne has been delayed by a forest protest.
Police in Tasmania say they have arrested six forest protesters who boarded the ferry.
Four protesters from the group Still Wild, Still Threatened abseiled down one side of the ship and unfurled a banner that read Still Woodchipping the Spirit of Tasmania.
The protesters are calling for an immediate end to logging in Tasmania's ancient forests.
The TT-Line says the protesters actions were grossly irresponsible and placed lives at risk.
Still Wild, Still Threatened spokeswoman Ula Majewski says the protest is part of a worldwide campaign to save Tasmania's forests.
"This peaceful protest up in Devonport tonight signals the start of Australia's involvement in the international 24 hours of action for Tasmania's ancient forests, which is happening in 21 countries across the globe," she said.
The ferry left Devonport about 9:30pm local time, two hours behind schedule