How ultra-marathon athlete Jono Ridler will swim 100km across the Hauraki Gulf

Ocean swimmers are typically apprehensive about things like sharks, swells and freezing cold water – but for Kiwi ultra-marathon athlete Jono Ridler, none of that compares to how he’s about to tackle “sleep deprivation” in the water.

Next week, Ridler will set off from Karaka Bay, Aotea Great Barrier Island to swim 100 kilometres (equalling about 35 hours) before arriving at Auckland’s Narrow Neck beach more than a day later – and he’s hoping to earn a New Zealand record in doing so.

Ridler told the Herald the biggest danger he’ll face crossing the Hauraki Gulf won’t necessarily be marine life or bad weather, but whether he becomes too exhausted to finish the race unassisted.

Once just an “average swimmer”, Ridler has now become no stranger to long open-water swims and is one of 10 to have completed New Zealand’s “triple crown” of endurance by swimming 23km across Cook Strait in 2019, 40.4km up Lake Taupō in 2020 and 28.6km across Foveaux Strait in 2021.

The Hauraki Gulf will be his longest swim yet, a distance greater than all of his previous “triple crown” swims combined.

“The biggest risk for me personally – and one that I’m really working on – is the combination of fatigue, sleep deprivation and hypothermia,” Ridler said.

“When those things come together, I think, that could be quite difficult to work through. It’s as much a physical game as it is a mental game. If I can push through that and if I can keep the support crew pushing me as well, I think we can get through it.”

The 33-year-old has spent eight months preparing for the Hauraki Gulf, and he said doing so for “such a long period of time” has been “interesting”.

Next week, Ridler will set off from Karaka Bay, Aotea Great Barrier Island to swim 100 kilometres (equalling about 35 hours) before arriving at Auckland’s Narrow Neck beach more than a day later – and he's hoping to earn a New Zealand record in doing so. Photo / Subzero Images

“I’ve been hammering myself over the last eight months to get myself into a state where I am going to be ready.

“I have stayed up during the night swimming – waking up at you know, stupid o’clock in the morning to go for one of my long ocean swims to get a sense of what it feels like.

The “build phase” of Ridler’s training finished a couple of weeks before when he’ll be setting off, which culminated in 28 hours of swimming over Easter weekend.

Now, during the final days before take-off, the Aucklander has been spending time in ice baths, “preparing for the colds and tapering a little bit” to get his body “feeling good”.

To break the record, Ridler must swim ‘unassisted’, which covers a few regulations.

A wetsuit can’t be worn, Ridler said.

”It’s a pair of togs that are below the waist and above the knees, one cap, one pair of goggles, and you can’t touch the boat at any point.”

Ridler said when he’s eating, he’ll be treading water, and he’ll be mostly having liquid feeds throughout the course of the 35-odd hours.

He also expects some solid food will be in the mix, including blended carbohydrate/protein drinks, electrolytes and bananas and gels that easily absorb into the system.

Ridler explained there’ll also be some room for treats like chocolate bars just to keep him sane and awake.

Once Ridler is in the water, decision-making will be out of his hands, and a governance system is in place in case something goes wrong.

“If I get into a state of hypothermia, I won’t be thinking straight, and that decision-making then goes to the crew. The lead observer and the medic [will] be able to make a decision on whether I get pulled or not.”

In addition to pushing the envelope of human endurance, Ridler said he hopes to motivate immediate action to safeguard and improve the health of the Hauraki Gulf.

He said the swim “acknowledges the significance and value of the Gulf, and also acts as a call to Government to move now to protect and restore it”, and he’s working in collaboration with Live Ocean, founded by acclaimed sailors Blair Tuke and Peter Burling.

Now, Ridler anxiously waits for that window (between April 25 and May 5), hoping the weather will play ball.

“We’re going to be aiming for the best weather window possible,” said Ridler.