Ten years ago, when the 2.5km Ruby Swim in Lake Wānaka began, the race directors were stunned that 190 people turned up.
Jamie Norman and Eddie Spearing hoped for 25. Today there will be 500. The numbers are capped and entries have closed.
A decade ago, all they wanted to do was create something special, the "best little swim" in the district, and had no idea how popular the event and open-water swimming would become, they said this week.
They still believe they have "the best little swim", but have responded to swimmers’ demand to swim further.
The distances now include a 10km, 5km, 3.8km, 2.5km, 1.2km, 600m and 200m race.
Several age groups and separate categories for adaptive swimmers and togs or wetsuit wearers have also been created.
This year, the new category is called "The Immortals", for competitors aged 80-plus. Four seniors entered, although two withdrew earlier this week.
