Jonathan Ridler - Foveaux Strait

Stewart Island to South Island

28.6 km (17.8 miles)

7 hours, 52 minutes on 22 February 2021

Observed and documented by Simon Olliver

Course Record



  • Name: Jonathan Ridler
  • Gender: male
  • Age on swim date: 31
  • Nationality: New Zealand
  • Resides: Auckland

Support Personnel

  • Belinda Donaldson - lead crew
  • Breanna Ward - feeder
  • Camille Gluck - feeder
  • Sarah Elizabeth - lead feeder
  • Simon Olliver - observer

Escort Vessels & Pilots

Pilots Rewi Bull, Paula Bull, Reti Bull, Sonia, and Rahiti piloting vessel Shangri La, harboured in Bluff, New Zealand.

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Standard (speedos) swimwear, standard googles and one swim hat.
  • Sanctioning: This swim is co-ratified with the New Zealand Open Water Swimming Association (NZOWSA).

Route Definition

The Saddle, Stewart Island to the Invercargill Heads, South Island

  • Body of Water: Foveaux Strait, South Pacific Ocean
  • Route Type: one-way channel swim
  • Start Location: The Saddle, Stewart Island (-46.720811, 167.977390)
  • Finish Location: Invercargill Heads, South Island (-46.585446, 168.276754)
  • Minimum Route Distance: 28.6 km (17.8 miles)


LongSwimsDB: Foveaux Strait.

Swim Data

  • Start: 22 February 2021, 08:23 (New Zealand Daylight Time, Pacific/Auckland, UTC+13).
  • Finish: 22 February 2021, 16:15
  • Elapsed: 7 hours, 52 minutes.

Summary of Conditions

Feature Min Max
Water Temp (C) 14.5 16.3
Air Temp (C) 11 16
Wind (kph) 5 15

GPS Track

Trackpoint frequency: 20 minutes. Download raw data (CSV).

Click to expand map.

Speed Plot

Nutrition: Pure gels and carbohydrate/ protein sports fuel and Perpetuem. Feeding every 30 minutes from bottle off the IRB.

Observer Log

Download PDF


by Jono Ridler

On Monday, I broke the record for the fastest crossing of Foveaux Strait, completing the swim in 7 hours and 52 minutes. It still feels quite surreal to write that. In doing so, I also became the 10th person to successfully swim Foveaux Strait (following marathon swimming rules) and the 7th person to complete the New Zealand Triple Crown of Marathon Swimming – made up of Cook Strait, Lake Taupo, and Foveaux Strait – and with the fastest combined time by 3 hours.

It all came together in the most magnificent way. Here is the story (grab a cup of tea for this one!).

I first envisaged doing this swim in 2019, in the lead-up to Lake Taupo. At that time, all focus was on the Lake Taupo swim attempt, and so Foveaux Strait was only given a cursory thought and a phone call or two. It would not be until April of 2020 that I started to look at the swim more seriously, initiating conversations with swimmers who had completed the crossing previously to understand what it would take to pull a swim attempt together. Foveaux Strait is unique in that there is currently no organisation that oversees the coordination of the swim. All of the logistical planning is essentially built up from scratch.

I committed to an attempt before winter, and so began a long 9-month training regime in the lead-up to the swim. I won’t bore you with all the details of this. In summary, there were a lot of early mornings, long swims in cold water (some starting in the dark), weekends spent at the pool, ice baths for more than an hour in duration, and eating like there was no tomorrow. But it wasn’t just getting familiar with the distance and the cold – I trained to be consistently fast and moulded my body to be comfortable with holding pace.

There were many times where the swim may not have eventuated. I was made to change boat pilots – twice – one of which was only two days prior to the swim attempt. Lockdown hit Auckland the week prior, and I was forced into the position of fleeing the city to have any form of certainty around travel down south (fortunately, as we know, the lockdown was lifted a few days following). Work and life was beyond busy and it was difficult to balance it all.

But there was a sense that it was all going to work out. That it was meant to be.

We edged closer and eventually into the tide window – a period of 5 days on the neap tide where the tidal coefficient was at its lowest. The decision was eventually made that Monday would be the day, and the forecast was improving every day. The long-range forecast initially stated a 12-knot northerly wind moving to 6-knots variable as the day went on; as we came closer to the day, it was forecast for 6-knots northerly in the morning and 2-knots variable by midday! We couldn’t let an opportunity like that pass up. We booked flights for Sunday and the crew started coming in from various parts of the country. After convening with the crew on Sunday evening, we decided to start at 8:30am – approximately two hours before high tide.

I tried to sleep that night. I meditated, took medicine, and counted sheep (forwards and backwards). Eventually, Sarah suggested placing a wet face-towel over my eyes to keep them closed. This did the trick, and I fortunately was able to get just over 3 hours of sleep. This may not sound like much, but there was a point where I was preparing myself for taking on the swim with no sleep. Marathon swimmers reading this will understand this quandary with familiarity.

The next morning, we assembled at just after 5am to begin our journey from Bluff to Stewart Island. We were greeted by the most beautiful sunrise. There was very little wind, with only a slow south-west swell rolling through. There was a boding sense that this was going to be a special day. The journey to Saddle Point on Stewart Island, our starting point, took just under two and a half hours, and so there was adequate time to grease up and get all of the equipment in order once we arrived. I jumped onto the IRB once the outboard was warmed up and, without too much ceremony, dropped off the side and into the water to make my way to the starting point. I touched the shoreline, the whistle blew, and we were off.

I started off well, holding a speed that was at the edge of my aerobic capacity but without over-reaching. I knew that I needed to hold that pace for the duration of the swim, and it would have been counter-productive to go too hard at the start. It was easier to hold a good rhythm at the start of the swim. The taper had clearly worked; my body felt incredible. However, my body degraded, predictably, as the swim went on, and muscle aches started to creep in making it harder to hold the same speed. This is where the mental training came into its own, and I held the pace as well as possible regardless of the pain that I was feeling.

The conditions, all in all, were incredible, and I could not have asked for better. At times, I had to remind myself that I was swimming through an open channel of water and not a lake. It was glorious. Only toward the latter part of the swim, over the last hour or so, did the water chop up slightly, with a breeze brought in from the south-east. Visibility in the water was near perfect, and I could see as far as my eyes would allow.

The water was slightly cooler off Stewart Island, somewhere near 14C. It warmed slightly as the day went on, moving to 15C or so through the Strait, and 16C an hour off the mainland. Currents through the middle of the Strait carried both cold and warm water, interspersed with such frequency (often less than 5 seconds apart) that it became difficult to maintain thermoregulation at times. However, in all, there were no concerns with the cold, and I only ever reached a two out of ten on the self-regulated “cold scale”.

We did encounter a small amount of marine life during the swim (read: sharks). There was one visitor that held near the surface apparently 15 metres or so away from where I swam. It did not prove to be a nuisance of any kind. I could see the crew standing and pointing at some object in the distance but was not concerned with looking as this would have been both a waste of energy and a break in rhythm. The shark sighting was not mentioned until after the swim, which was tactful. I also swam over a group of about 20 sharks halfway through the swim, moving in a slow circling formation well below me in the distance and far enough below that I felt curiosity over fear – although, I did yell “shit!” to the crew in the IRB on my left as I breathed during a stroke, shortly after seeing them. The shark-shield marine repellent device gave me piece of mind in this, and, as an added extra, an unfortunate electric shock to the torso when I swam into it.

Eventually, we found our way to the mainland and the end of the swim. The team had navigated the tidal flows almost perfectly, although we had to cut against the ebbing tide for the last period of the swim, slightly delaying the finish time. On my invitation, friend and supporter Camille gladly jumped in for the final mile, and I was happy to have the company. We swam through a flock of hundreds of muttonbird to the finish point, with the birds swirling around us everywhere and their discharge swirling with an equally strong presence in the water beneath us. It was a surreal moment to cap off what had been a surreal day.

I touched the natural part of the shore, and the swim was done. With that, I had crossed Foveaux Strait and completed the Triple Crown. I was hauled back onto the IRB and ferried to the Shangri La, and with that we made our way back to Bluff harbour.

What a day it was. These are the days that we live for.

The crew that made it all happen and to which I owe a debt of gratitude:

Rewi Bull (skipper of the Shangri La), Reti Bull, Paula Bull, and Sonia Rahiti of Invercargill; Owen, Scott, and Timothy of Oreti Surf Club; swimming friends Camille Gulick, Belinda Donaldson, Simon Olliver, and Breanna Ward; father Gordon Ridler who supported from land; and last, but certainly not least, my fiancé Sarah Elizabeth.


Click to enlarge.