I'm nervous. Everything is riding on this last lap. The ultimate father/son showdown will be settled in the next 30 seconds. The prize? Boasting rights for years to come. I edge towards the start line, anxiously gripping the steering wheel. All I need to do is beat 25.22 …
The venue for this head-to-head is Superthriller Jetsprint, a purpose-built jetboating facility next to Auckland Airport. It's the only location in New Zealand where you can drive a jetboat so it's the perfect place for settling family rivalries.
Instructor Nick Greenslade talks us through the controls. There's a steering wheel, an accelerator and a gear lever with forward and reverse. That's it. No rudder and no brake. "Don't worry," he says, smiling, "I have a kill switch."
There are two tracks – Alpha and Whiskey – marked by coloured buoys on a man-made lake. Greenslade suggests the trickier Alpha course and I notice the fastest time on the leaderboard is 22.90 – set, of course, by him.
During the practice laps, Dad and I tentatively feel our way around, taking it in turns to drive while the other navigates. Thanks to the boat's 100-horsepower engine and lightweight aluminium hull, it's incredibly responsive and surprisingly easy to drive. The only counter-intuitive concept is you need power to steer, whereas instinctively you take your foot off the gas when things go wrong. Dad finds this particularly challenging because he suffers from a rare affliction called buoy blindness, where he frequently ignores the course (and my advice from the passenger seat) and instead charts his own more creative route.
Then Greenslade jumps in and shows us how it's done. Throwing up huge plumes of spray, he expertly drifts the boat around the course and roars across the finish line in 23.24. It's a thrilling, masterful display of how ridiculously agile a jetboat can be in the right hands.
Of course, the aim is to have fun and Greenslade urges us to go at whatever speed we feel comfortable. He's instructed everyone from teenagers to octogenarians and he says people always improve during the session. He tells us about a 14-year-old girl who was reluctant to drive but was coaxed into it by her dad. Over three laps she cut her time from a minute to 28 seconds and finished grinning like a champion.
With the practice laps done, it's time to race. Three laps each with the best time taking the podium. Dad starts well but buoy blindness strikes again and he loses precious time making corrections. Then, miraculously, on his last lap everything comes together and he posts an alarmingly quick time of 25.22.
Then, it's my turn. On the first lap I run wide and the best I can muster is 27.77. The second run is better but I'm still slower at 26.17. And so – just like in the movies – it all comes down to the last lap.
As soon as the green start light appears, I floor it. Buoys flash by in a blur as I power around the first bend and speed down the straight. I misjudge the far corner but make up some time coming back. One last turn and I blast over the line.
The time? 24.92. Just quicker than Dad but still two seconds slower than Greenslade. The relief is palpable. Boasting rights are safe. At least, for now. My three siblings might disagree.
Colin Dale Motorsport Park, 87 Prices Road, Manukau, Auckland. A three-lap session costs $NZ165 per person (min two people). See superthriller.co.nz
Rob McFarland was a guest of Superthriller Jetsprint.