Ruairi Griffen has invented, and helped build, a wave-powered machine which tows surfers out beyond the breakers.
Ruairi and the machine will feature in tomorrow's TV2's Let's Get Inventin' show, which turns young inventors' ideas into reality.
For Ruairi, a keen boogie boarder at Aramoana, the invention was a means to an end.
"It's pretty tiring paddling out beyond the breakers. Sometimes, when you finally get out there, you're too tired to catch a wave and surf back in - especially in the cold water around Dunedin.
"This invention means you can surf for a lot longer - if you can stand the cold."
Ruairi's Swell Generator is this series' most complex invention, which uses a buoy, high-tech anchors, push bikes and lots of rope to produce enough energy from the swell to power a surf tow.
The power of the waves pulls a buoy up and down, in turn pulling a rope that turns a flywheel.
Power generated is stored in car batteries and then run to wheelchair motors which drive a surf-tow machine.
The surf tow allows surfers to grab a rope to be towed out beyond the breakers on their surf boards instead of having to paddle all the way there.
When the water got too cold, the Swell Generator could be used to power a water-heating element so surfers could have a hot shower on the beach to warm up.
