Who would have thought the humble Kiwi jetboat, first used to help with sheep mustering in the hard-to-get-to places of the high country, would lead to the most glamorous and dangerous form of surfing?

You see, if Bill Hamilton (later Sir Bill) hadn't invented his own propulsion system to navigate the shallow river braids of his native South Canterbury in the 1950s, then we might never have had jet skis which now tow surfers into monster, two-storey high waves.

"We see the big heroes of Hawaii charging down these big waves, and it's a product of two New Zealand inventions: the jetboat and the board design," says Kiwi film-maker and adventurer Clive Neeson.

Neeson's eco-adventure film, Last Paradise, which screens at this year's Film Festival, is about such innovations and has been 45 years in the making.

It tells the story of how extreme sports evolved thanks to the Kiwi No 8 wire mentality and a handful of adventurous, not to mention crazy, pioneers like bungy king A.J. Hackett, Taranaki surfboard maker Dave "Biggie" Smithers, and Neeson himself who filmed many of their daring exploits throughout the 60s and 70s.

"We bumped into each other, so from a very young age there was a handful of guys from around the country who knew each other and had this common vision to take what they really loved and evolve it.

"They were all mavericks who through their love of what they were doing ended up evolving into something that has become mainstream."

It started with surfing, with these young friends travelling the world chasing bigger and better waves in places no one had ever surfed, and that led to everything from snowboarding to bungy jumping being created.

There were also more modest advances, like fashioning their own leg ropes and Smithers using a sink plunger to mount a mast and sail to his surfboard to make a wind surfer ("It worked great.").

"It's not about what we had here, but what we didn't have here," says Neeson, who lives in Oakura near New Plymouth, and just down the road from Smithers' surfboard making business.

"All the people in this movie had pretty deprived backgrounds, they invented their own games and own toys and through a lifetime they turned it into not only a mainstream interest but one of the biggest industries in New Zealand.

"And so it's really the story of how what some people call Kiwi ingenuity, led to the phenomenon of modern extreme sports. And these days we're renowned as the capital of extreme sports and that story has never been told before."

As Hackett says in the film: "One of the things I used to enjoy most when I was a kid was jumping off cliffs and bridges. But there's a limit you can go to - after about 40 or 50 feet, when you hit the water, it really hurt."

So a little later on in life he came up with the bungy, and to show the idea to the world he jumped off the Eiffel Tower - the footage included here shows the jump and him being carted off by French police.

"Then we had to figure out a way to jump the masses," he says in the film.

The impetus for Last Paradise finally being made came when Neeson got a chance to use the facilities at Peter Jackson's Park Road Post in Wellington in 2007 to restore and remaster the footage (shot on a number of different formats).

Around 70 per cent of the footage was shot by Neeson, but he also knew other people who were documenting what was going on back then, and set about tracking down their film.

"I did a deal with them to remaster all their footage, which was mostly rotting anyway in dark closets, so any footage of high quality that I knew of was remastered under the project - and restored into big screen format."

The footage from the 60s and 70s is stunning, whether it's surfing at Raglan or remote parts of Australia, to hang-gliding above the Tasman Glacier and the Southern Alps, which is taken from Michael Firth's hit 1970s hang-gliding and ski doco Off the Edge.

While this untold story of extreme sports, and the action are riveting, Neeson says the main objective of the film is to celebrate New Zealand's "extraordinary physical beauty", its "scientific legacy", and the country's innovators.

"The purpose of the movie is to educate on science and innovation. To recruit the younger generation back into science and make it cool again, because it's through science we will find painless solutions to the problems we face in the world."

What: Last Paradise, an eco-adventure film about the evolution of extreme sports in New Zealand
Who: Clive Neeson, filmmaker and adventurer
Where & when: July 23, 8.30pm; July 25, 11.15am, Sky City Theatre