Six events were on offer, ranging from a 200m dash for children up to a 10km marathon.
The feature swim, The Ruby, a 2.5km circuit from Waterfall Creek around Ruby Island, was won by Invercargill’s Jaxon Taylor, who snared first place in the dying stages of the race, blitzing ahead of Dunedin’s Stefannie Gillespie, to win by just seven seconds in a time of 33min 26sec.
"I’m pretty sore, it was brutal racing.
"I don’t usually do this long sort of stuff so I didn’t really know how to pace myself."
A packed field made the start a struggle for Taylor, who said he was "swamped" and nearly lost his cap.
But he pushed his way to the front of the field and from there was fighting against strong winds that lashed across the lake, most notably around the back of Ruby Island.
"It was quite choppy. It was actually quite nice going out and back in to shore, but round the back it was rough and you started to lose your stroke a bit," Taylor said.
In the other races, Dunedin’s Jack Divers took the crown in the Big Ruby 3.8km race, in a time of 50min 27sec, while Adam O’Bryne won the 10km in 2hr 42min 12sec.
Queenstown’s Sam Davis won the 1.2km Return of The Jetty race in 20min 36sec and Lara Tyndall of Dunedin swam strongly to claim the 600m Island title in 12min 15sec. Wanaka youngster Max Good won the 200m Little Gems race in 2min flat.