"We've both been in the sport since we were like five years old. It's been in our family for ages.
"We do about one-and-a half-hours on the water every second day so it's quite an intense schedule. We're making sure we get as much training in as we can."
Tane, the youngest member of the men's squad, said they've been really working incredibly hard to get ready for a big challenge.
"I suppose, to get ready to take on those guys, we've been really focused on our nutrition and things like that. We're making sure we are training really hard," he said.
"The races are spread out over 30km so it is pretty full on. I don't really know how I mentally prepare. All I worry about is doing my best and letting the rest sort itself out.
"It is tough going up against the older boys. They're a bit bigger and stronger which is a challenge but it's something I'm definitely up for."
The races they'll be competing in cover 27km and they'll be up against the best the world has to offer, including the Tahitians who are the All Blacks of Waka Ama.
Zane said she prefers the longer distance over the sprints, though the Tahitians have a different definition of sprints to New Zealand.
"Sprints are a real burst race. With the longer ones it's a bit more relaxed and you're more worried about saving your energy over 30km," she said.
"We're just doing long distance races over there. There are sprints the following year but they're a bit more intense than ours.
"Tahiti's sprints are like 4km and ours are usually around 500m!"
With Waka Ama being such a big part of their lives, Tane said it's been really good to have a great support system around them.
"Family, friends and coaches have all been really supportive and involved in us so they're all pretty influential people in our development," he said.
"Steve Rolleston has been hugely helpful for me, he's been really good about telling me things to do with training and technique."
The Heta siblings aren't the only Northlanders heading to Tahiti.
Ngaire Pehi is in the NZ Masters Women team, while Greg Jones, Jason Eruera and Richard Pehi will line up for the NZ Masters Men.
Tupu King will paddle with the NZ Open Men squad.