It was still dark when Quinn Boyle took his first steps into the water on the southern shores of Lake Taupō last Wednesday.
The clock said 4am, cloud cover meant it would be another three hours before the sun came out and Quinn, from Ōtamarākau, wouldn't leave the water for another 13 hours and 46 minutes.
The 15-year-old's destination was Taupō itself - 40.2km away.
When he reached that destination, he became the second-youngest male to swim the full length of the lake.
Quinn was due to tackle the marathon swim last March, but Covid 19 restrictions prevented his attempt.
He says he felt nervous and excited, but confident, before the swim.
''I couldn't wait to get started,'' he says.
At the end he was sunburnt, but ''just happy really''.
The swim was overseen by Quinn's open water swim coach Sheryl McLay and open water swimming legend and swim guide Philip Rush, who specialises in guiding swimmers attempting the Taupō swim and Cook Strait crossing. Both have first-hand experience of the lake swim, and Philip made a double crossing in 1985.
''For his age he swam incredibly well to cover the 40.2km,'' says Philip. ''Actually I think it was 41.6km with a few deviations.''
Philip says Quinn showed maturity beyond his years.
''He swam it without any complaints - he just got on with his job. We had a game plan before we started. It's a very large body of water and we just wanted to get on and get the job done and he did that to perfection.''
For the final 6km Quinn stepped up his efforts, with Philip's encouragement.
''He got better technique-wise and that made him go faster,'' says Philip.
Keeping energy levels up is one of the keys to success and Quinn ate and drank electrolyte drinks, energy gels and peanut butter sandwiches. But at each refuelling, he was not allowed to touch the support craft.
Sheryl says it takes ''intestinal fortitude'' to complete the swim.
''There are two things you need to do. The first is have the base fitness, strength and endurance, and you can only get that from doing some big miles in the pool, and the other side of it is learning to swim in the open water.''
As part of his training, Quinn swam from Moutohora (Whale) Island to Whakatāne Heads in early December and did an eight-hour double crossing of Lake Rotoiti later in the month.
''He showed maturity and he's done something you certainly wouldn't expect of a 15-year-old,'' says Sheryl.
While Quinn took an impressive sixth place in the 10km event at the New Zealand Open Swimming Championships this year, his interest lies in solo swims, with crossing Cook Strait one of his goals.
Both he and Philip say that could be some time off. Being prepared to swim in much colder water is one of the challenges of the crossing.
''He's still very slight and we don't do these things in wetsuits,'' says Philip, ''so we've got some work to do on that, but it's something we can build on.''
One of the reasons for doing the swim was to raise money for his former school Ōtamarākau, which missed out on its annual fundraising fishing competition last year.
Money can be donated via a givealittle page. Other money raised by the swim will go to the Cancer Society.