New Zealand organizers have built a waterslide with the aim to raise money for people with depression. Credit LiveMoreAwesome

ARMED with two shovels, and with the help of an excavator, two New Zealand men have dug the world's longest, and possibly muddiest, waterslide.

Mates Jimi Hunt and Dan Drupstee dug the 650m slippery slide on a property at Helensville, northwest of Auckland and opened it this weekend as part of a festival to help combat depression.

Almost 1000 people, some of them naked, slid down the three slides - with 60m and 90m versions available - to help raise money for the Live More Awesome Charity.

"It was a kids playground for adults," Drupstee told the New Zealand Herald.

"Being a non-alcoholic event we wanted to take people back in time to their younger days when there were no worries and life was fun and easy. I think we achieved that."

The 650m monsters featured a luge-style trench cut through a cow paddock, complete with a tunnel where the slide goes under a fence.

In a video posted online, Drupstee said of the project: "We're a couple of Kiwi guys who like so many others have really suffered at hands of depression.

"It was really tough, but having come out the other side we decided the best way for us to keep depression at bay was to 'Live More Awesome'."