Hundreds of family and friends gathered to farewell the crews of two traditional Maori canoes, or waka, as they set off from Auckland's Viaduct Events Centre, bound for Easter Island (Rapanui).
The two double-hulled waka, with 10 crew members each, on Friday started their 19,000 kilometre journey without modern navigational aids, recreating Maori ancestral journeys.
The journey was expected to take six to eight weeks each way.
The waka don't have GPS or modern navigational tools on board, so the crews will be using only the stars, moon, sun, ocean currents, birds and marine life to guide them.
However, each waka does have a tracking device on board, as well as a satellite phone, in case of emergency.
The crew members' life jackets are also fitted with individual tracking devices.
The crew members will take turns sleeping in small compartments for three or four hours at a time, and will fish constantly for fresh food.
A small stock of fresh fruit and vegetables, meat, dry freeze foods, rice, noodles, canned food, water and vitamins will be on board, and the crew will take minimal clothes on the journey.
Several Royal New Zealand Navy vessels escorted the waka out of Waitemata Harbour.
Navigator Jack Thatcher earlier told AAP the first leg would be challenging with chilly temperatures, but winds were forecast to be favourable.
"You always run into things like that but it's about learning to relate to the ocean environment and just going with whatever it throws at you."
The expedition, named Waka Tapu or Sacred Canoe and 20 years in the making, has been organised by the New Zealand Maori Arts and Crafts Institute and Te Taitokerau Tarai Waka.
Mr Thatcher said it could be followed on the Waka Tapu website with regular updates from satellite tracking.