A North East Victorian endurance athlete has returned home after an extraordinary attempt to complete what is believed to be the first ever triathlon the full length of New Zealand.

Laura Marshall, 49, who is based just outside Wangaratta in Peechelba, has spent 45 days cycling, swimming and running from the top of the North Island to the very bottom of the South Island in a mammoth personal challenge she calls 'The Long Tri NZ'.

Starting at Cape Reinga on February 24, Marshall set out to link together the three classic triathlon disciplines across the entirety of Aotearoa.

It is not an official race or sanctioned event but a self-designed endurance journey that, through research, she believes no one has completed before.

“The The Long Tri NZ is not an official event, not a race, not something you can sign up for,” Marshall said.

“It’s a dream-built adventure triathlon that strings together the whole of Aotearoa.”

The journey began with a 12-day cycle down the length of the North Island, covering 1172.56 kilometres and more than 14,000 metres of elevation.

Marshall rode through hills, headwinds, coastal stretches and small towns, absorbing the country at road level.

From there came the most daunting single leg of the entire challenge.

The Cook Strait swim, completed south to north, covered 36.9 kilometres in cold and unpredictable conditions.

Marshall spent 14 hours and 41 minutes in the water, with average temperatures hovering around 14 degrees.

“The water was choppy from the beginning, some big waves and strong currents that affect your stroke and rhythm, causing a long 14-hour swim,” she said.

“This was accompanied by a lot of jellyfish stings.”

Marshall said that leg would not have been possible without her support crew.

“Erin and Peta kept my spirits high, kept my nutrition and hydration on track,” she said.

“It was definitely a team that got across the Cook Strait.”

After reaching the South Island, Marshall transitioned into the final leg, a run and walk from Picton to Bluff that took a further 26 days.

She averaged around 40 kilometres a day, eventually covering 955.21 kilometres with almost 8700 metres of climbing.

“From Picton to the Bluff, it was a mix of determination, amazing scenery and a lot of snacks,” Marshall said.

In total, Marshall was on the move for 39 active days, with six additional rest and logistical days.

Across all three disciplines she covered 2164.68 kilometres and climbed more than 22,000 metres.

While the physical scale of the challenge is staggering, Marshall said the idea itself had been brewing for nearly a decade.

“The thought for this adventure started about eight years ago, after I was lucky enough to complete the Enduroman Arch to Arc in Europe,” she said.

“I had this little thought that refused to go away.

“What if I did a triathlon the length of an entire country?”

New Zealand, she said, was the obvious place to try.

“The long white cloud had everything,” she said.

“A dramatic coastline to ride, a notorious stretch of ocean to swim, and a mountainous South Island to run.”

Marshall is no stranger to ultra-endurance feats.

In 2018 she became the first solo Australian woman to complete the Enduroman Arch to Arc, one of the world’s toughest triathlon-style challenges.

She said that experience gave her a vital blueprint for New Zealand.

“It gave me knowledge on what it felt like to take on a multi-day, multi-discipline challenge that pushes you right to the edge and then asks for a little bit more,” she said.

She credited coach Sarah from Dare to Train for structuring her preparation, and sports dietitian Christie Robson from Multisport Nutrition for helping dial in nutrition, particularly for the long, cold swim.

Despite the hardship, Marshall said the highlight was simply bringing an idea to life.

“I think the main highlight has simply been starting,” she said.

“Taking this idea that lived in my head for eight years and finally turning it into reality.”

She also spoke warmly of the people she met along the way.

“The people I’ve met have been incredible,” she said.

“Friendly locals and curious travellers.

“People would stop for a chat and offer encouragement.

“Those moments definitely made it valuable.”

Now back in Australia, Marshall said she was grateful for the belief and support behind her ambitious project.

“Thank you to everyone that believed in me and helped to make this adventure happen,” she said.

For a Peechelba-based athlete to take on two islands, an ocean crossing and thousands of kilometres under her own power, the journey has been as much about curiosity and resilience as it has been about endurance.

Whether or not records are ever formalised, Laura Marshall’s Long Tri NZ stands as a remarkable personal and sporting achievement.