Speaking to the Herald afterwards, McDonald, who competes on the Wing Foil World Tour, said he had been considering the challenge for more than a year and wanted to test himself both mentally and physically.
“I’m stoked to have got it done,” McDonald said. “I wanted to push my personal limits and I felt like I really did that.
“I’m not sure I could have gone much further. By the time I finished I was pretty close to hypothermia. I was completely out of it, struggling a lot and basically unable to walk once I got back in the boat and stopped.
“I wasn’t certain I was able to do it. I kept putting it off because I was pretty scared about it, so I didn’t plan as much as I should have. Then I just decided to lock in. I flew out there with only two weeks of planning and spent another two weeks getting ready.”
The previous 12-hour record stood at just over 350km, while the longest recorded effort before McDonald’s attempt was 405km over more than 13 hours.
The 24-year-old from Katikati said his initial goal was simply to break the 500km mark within 12 hours, something he achieved with only minutes to spare after suffering an early setback when he crashed and broke his sail.
To stay on schedule, McDonald spent five consecutive hours on the water before taking a brief stop on shore.
During that stretch he completed his longest uninterrupted ride on the foil, covering 172.1km without falling.
While the physical demands were immense, one of the biggest challenges was keeping himself fuelled. McDonald carried water, protein bars and energy gels in a backpack, but quickly grew tired of them.
He later switched to fruit and dried meat before reaching a point during the final 10 hours where he could barely eat at all.
Instead, he relied on chocolate milk and coffee.
“I had boat support during organised time slots where I needed to refill my water packs and food,” McDonald said.
“I’d ride past and grab the equipment like a shopping bag, put it into my backpack and replace the old one. I was doing that at about 30km/h.”
He also wore a headset and received phone calls from family and friends throughout the challenge to help him stay focused.
The overnight hours presented another obstacle. Once the sun finally dipped below the horizon after 11pm, the darkness made it almost impossible to spot debris in the water.
He crashed another seven times after hitting seaweed and what he believes was a fish. By the finish, the 13-degree water had taken a heavy toll.
Despite competing professionally on the Wing Foil World Tour, McDonald said the challenge reminded him why he first fell in love with the sport.
“My profession at the moment is competing against other people, which is very cool. “But I wanted to go back to the roots of why I do this, which is to push myself and see how far I can go.”
After completing the challenge, McDonald celebrated with a barbecue before beginning his recovery with sleep, ice baths and time in the sauna.
He also paid tribute to his partner, Chantelle Middleton, for helping organise the challenge, along with Giske IL Vannsport Club, which assisted with preparations and recruited volunteers to support the attempt.
After some recovery time, McDonald will turn his attention to next month’s Wing World Championships in Istanbul, Türkiye.
Beyond that, another endurance challenge is already on his mind. While he is yet to decide exactly what comes next, one idea is a wind-powered journey from the top of the North Island to the top of the South Island.
Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.