You might think that suffering from seasickness precludes a successful career as a powerboat racer. But as Jackie Hunt could tell you, you would be wrong.

This ebullient computer software salesperson from Hampshire goes green in the face at the merest suggestion of rolling motion on liners or ferries. But get her in the cockpit of a powerboat, spearing into 20-foot waves at speeds of more than 80mph, and she is literally in her element.

Since taking up racing on a whim as a 30-year-old in 1999, Hunt has made a name for herself in a sport that has traditionally been the preserve of high-octane alpha males - albeit that her name, from at least one of her rivals, has been "that girl". Hunt is not large - 5ft 2in and eight-and-a-half stone - but as her fellow racers soon discovered, she contains apparently boundless reserves of chutzpah.

So successful has Hunt been in her first season of Powerboat P1 racing that she will enter this weekend's final grand prix in Portugal with a genuine chance of becoming world champion in the SuperSport class.

Crowds of up to 80,000 are expected at the Marina de Cascais in Lisbon to see if Hunt's boat Arpro, which she has crewed to three wins in the past five grands prix with the navigational help of her husband Mike Shelton, can overhaul the gap of 30 points to the leaders Ocean Dragon, a boat owned and raced by Martin Lai, who runs a chain of restaurants in Devon.

With 100 points on offer for the winner of each of the two final races today and tomorrow, Hunt believes the Dragon is catchable. "We can do it," Hunt said. "If we win both races we will be champions. Martin wants to be the first Chinese competitor to win the world title, and I want to be the first woman. It will be tough competition on the water, but off the water we are really good friends."

Hunt believes the P1 category is ideally balanced to favour the most skilful drivers, in contrast to Class One - effectively the Formula One of the sport, where money rules. While Class One racers habitually travel at speeds of up to 150mph, P1 racers have to average a top speed of 75mph in competition. That requires fine calculation of when to put the boot down and when to ease off.

Hunt seems positively euphoric in recalling harrowing details, such as in something called "stuffing it" when the boat "goes through the wave rather than across the top of it. It's not even like hitting a brick wall, it's like hitting a brick wall and then feeling it wrapping itself around you. You can't breathe, but the weirdest thing is the colours. As you go deeper and deeper, things go bluey-green, then brown, then black. Hopefully the boat springs back up again, but you can find yourself full of water."

Hunt is unusual in that she is responsible for both throttling and steering the boat, but, as she says: "I love power and speed. I also love freedom."