You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
One of the country's biggest off-road marathons will be held in Central Otago on August 28-29.
The Great Naseby Water Race is not for the faint-hearted, organisers say.
In its ninth year, the water race boasts trail races of 50km to 160km around a 10km loop at Naseby Forest.
One half of the loop follows a gravel road and the other a water race, which was originally built for gold mining in 1860 and now helps supply Naseby.
Organiser Jamie Sinclair said it was not a ''namby-pamby'' event, but was designed for people to challenge and extend themselves as runners.
The best thing about the event was finishing it, he said.
A 100-mile (160km) race would be held on Friday and other races, including 50km, 80km, 100km and a 60km team race, on Saturday.
Numbers were not confirmed but it appeared there would be more than last year's 152 entries.
The event would see many of the ''repeat attenders'' return to the race, he said.
The bulk of the entries came from Christchurch, Dunedin and Southland. A prize-giving would be held on the Sunday at the Naseby Town Hall.