Turtles normally make long-distance migrations, but this one is getting a lift with scientists back to more familiar territory in the Kermadecs.
The hawksbill sea turtle, named Koha, is aboard the NIWA research ship Tangaroa, which is leaving Auckland on Thursday for a 20-day scientific expedition in the area, about 1000km northeast of New Zealand.
The plan is to release it on Saturday morning near Raoul Island, providing the weather is calm.
Koha was found weak and emaciated near Dargaville more than two years ago and has since been nursed back to health at Kelly Tarlton's aquarium.
"It is a rare privilege to be able to return a critically endangered creature to its natural habitat," said voyage leader Malcolm Clark.
"We are very much looking forward to releasing it, knowing we have played a small part in helping the conservation of this magnificent species."
Kelly Tarlton's turtle expert Harry Josephson-Rutter says it is likely Koha was swimming in New Zealand waters as part of its early years but hawksbills prefer warmer waters.
The species, which can grow up to 1m long and about 70kg, was hunted to near-extinction because of its attractive shell but also now faces the threat of ocean pollution and habitat destruction.