The waka Haunui, which sailed into Wanganui on Wednesday, has travelled all the way from New Zealand to San Francisco with nothing but the sun, moon and stars to guide it.
Navigator Toiora Hawira, 21, said it's all part of running the waka traditionally, aside from the solar-powered motor for light winds or getting in and out of port.
"In times when you've got no celestial clues, like when it's cloudy, you wait for sunrise and sunset," said Mr Hawira.
"You take your first glimpse of the sun and take your bearings off it."
Haunui's kaihautu, or co-ordinator, Hoturoa Kerr, said people often don't believe the waka can be navigated without modern instruments.
"Everywhere they're quite surprised to see something like this," Mr Kerr said.
"People don't know anything about them."
Mr Hawira has been on river waka since he was 8 years old, and came aboard Haunui in 2012 for a voyage to Easter Island.
"Once I saw a big waka like this I thought 'I want to go on that'!"
Haunui has been to numerous islands and countries, including Tahiti, Rarotonga, Hawaii, San Francisco, and Mexico, usually with a crew of about 12.
It had a crew of 10 on its voyage up and down New Zealand, which began in Auckland in March. They travelled from there to Kawhia in seven days, then Porirua in three.
Tomorrow they will leave for Nelson, and they will also be visiting Christchurch, Dunedin, Bluff, and maybe Stewart Island, weather permitting, before heading up the coast to Auckland.
Flocks of schoolchildren were at the wharf on Wednesday to see the waka, while Mr Hawira explained the ins and outs.
Te Kura O Kokohuia School syndicate leader Gerald Patea said it was important for the children to see it because it was a reminder of the journeys their ancestors undertook.
"We want them to realise what that journey was," Mr Patea said.
"Our people are sea people, too."
Mr Hawira said Haunui's journeys were to promote global awareness of the sea, and guardianship of the ocean.
He said they saw everything out at sea from whales, sharks and dolphins, to the Southern Lights.
"We catch fish that you can't even carry, fish almost as long as your body," he said. "We've seen lunar rainbows, double and triple rainbows. We saw these white lights, just going straight up."
Mr Hawira said travelling on the waka gave him a sense of belonging and the way of life.
"The beauty about it is you get to see the islands from how our ancestors would have seen it in a way.
"All the stories we heard as kids about our great chiefs coming over on these waka, when you're on one of these you get the true feeling of it."
He said their journeys were "reviving history".
Sometimes they would pick new crew members up when they stopped off in towns and cities, if the person showed a real interest in waka voyages.
Mr Kerr had been voyaging for 30 years, and had been on Haunui since it launched in 2010.
He said the journey to San Francisco took more than a year, and they stopped in numerous places.
"I suppose the most interesting part is meeting all the people when you stop off at different islands," he said.
Planning was a big part of their trips, and he said too many people thought Maori did things on the spur of the moment.
"People think Maori have this 'oh, she'll be right' attitude and that's not what this is about," he said. "You would never survive on here if you had that kind of attitude."
Mr Kerr said it was important to teach people about this way of travel because so many did not realise it was real.
"People have been told that this kind of stuff is just all fairytales," he said. "The stories of our ancestors are actually real stories. They shouldn't be relegated to that realm of myth and legend."