About 40 swimmers lined the Portobello jetty before jumping into Otago Harbour, coinciding with the programme launch of this year’s Wild Dunedin — New Zealand Festival of Nature.
Starting from the jetty, swimmers made their way clockwise around Pudding Island/Titeremoana before returning — a total of about 1.5km.
Hosted by the Sunday Swim Squad, who swim in Otago Harbour twice a week, the event was open to members of the public.
Swim squad member and festival contributor Jo Woolley said open water swimming was usually colder and required a wetsuit, but also connected participants with nature.
"Because of the colder temperature it often wakes up the senses, makes you feel more alive."
The event had been run twice before but was brought forward from April to March this year to take advantage of the warmer temperatures.
Swimming in open water was a chance to appreciate the natural world and increase awareness of how people were treating the planet, Ms Woolley said.
Macandrew Bay resident Lucy Goldsmith said she was supporting her 10-year-old daughter Freya Lester for her first time swimming in open water.
They regularly swam at their local beach, so were prepared for the temperature.
She had never been up close to Pudding Island before and the distance between it and the jetty looked "achievable", Ms Goldsmith said.
Freya said swimming in open water was "just better than a pool".
The festival will run from April 10 to 22.
