It's carrying MetService and GNS Science staff - who'll carry out essential tasks, including maintenance of critical weather and tsunami warning systems.
The sailing was planned for a week ago - but delayed because of Auckland's Covid-19 Level 3 restrictions.
Maritime Component Commander Commodore Mat Williams says the mission left yesterday and work will be carried out of the next week.
It's the first major resupply mission in a year ... since DOC staff left the island.