A thrill ride leaves Barney McDonald wanting more.
If you've ever attended a Formula One grand prix, you will understand the thrill and intensity of the futuristic cars as they defy logic at unbelievable speeds. Jet boating is a little like that.
Except, you're on the water, someone else is driving and you get to enjoy the view.
Discovery Jet boat tours on the Rakaia Gorge, about 45 minutes' drive west of Christchurch, is a thrill-seekers wonderland.
The boats hurtle past sheer cliff faces, skim across shingle beds and round one jaw-dropping corner after another.
Recently purchased by Cantabrian lad Blair Grice, who worked for the company for three years before becoming its boss, Discovery Jet boasts similar thrills to Queenstown's famous Shotover Jet, but has the added attraction of the snowy Southern Alps framing the horizon and a range of "safari" options tailored to suit different tastes.
These include adrenalin-fuelled rides, a heli-jet combo, fishing remote stretches of the Rakaia or even alighting partway and walking back along the ridge of the river.
Grice is a personable chap, happy in his work and keen to point out the river's special features. These include towering coal and limestone cliffs carved out over millions of years. Grice also loves sending his boat into 360-degree spins, though he's kind enough to give a few seconds' notice each time and doesn't delight in soaking his passengers.
The trip starts a stone's throw from the Rakaia Gorge bridge, which carries State Highway 77 from Darfield to Methven, gateway to Mt Hutt.
The bridge was built in 1882 and is a striking platform from which to view the gorge swollen in flood.
On those occasions jet boating is not an option, with angry grey waters scaling the cliffs by several metres. Pick a sunny, clear day, however, and the river is paradise.
The grey and brown of the cliffs frequently give way to lush green pastures and bush, blue sky, snow-capped mountains and mesmerising blue waters apparently swarming with salmon and trout. It's hard to know where to look as the boat zips past the river's many nooks and crannies, but Grice knows the best vantage points and slows down or stops accordingly.
Tourism operators prioritise safety and Grice is no exception. Everyone wears a lifejacket and although the boat doesn't have seatbelts it never feels perilous, even during the spins.
The only downside to the experience is finishing.
As the boat pulls up to Grice's jetty it's tempting to ask him to take us out on the river again. In fact, why don't we?
Barney McDonald travelled as a guest of Christchurch & Canterbury Tourism.