The Great Naseby Water Race (GNWR) is an annual ultramarathon event from 27 to 30 August 2025 with multiple laps around a 10km course.
The course is set around a figure 8 10km loop - the first half along a gravel road and the second half on a forest track beside the water race that gives the event its name. There is no actual water running.
This unique ultramarathon event takes place near Naseby - the highest town in New Zealand at 2000ft. Naseby is 15km north-west by road from Ranfurly and 145km north-west (via Middlemarch) from Dunedin.