Oooooof! Hugh Jackman has just been punched, squarely, in the nuts. His body crumples inwards, hands instinctively headed southwards to cup his groin from further attack, and his eyes, which for a brief moment cross in pain, begin to water. As he struggles to catch his breath, his face contorted in a grimace, he raises an outstretched palm to surrender.

The great Aussie action hero has been vanquished, felled by something close to the wince-inducing blow that Jackman’s Wolverine delivered to the crotch of an enemy mutant in the most memorable fight scene of X-Men 3. His attacker, devoid of all mercy, lets out a long and sustained giggle. Jackman wags his head as if to shake off the pain the way a wet dog shakes off water. “No more hitting Daddy in the penis,” he finally croaks.

It’s a clear, crisp Sunday afternoon in Jackman’s home town of Sydney, Australia, and Jackman — along with his wife, Deborra-Lee Furness, and three-year-old daughter and assailant, Ava — is aboard a 48ft boat cutting its way across the waters of Sydney Harbour. It’s a leisurely family cruise. Jackman is loose and relaxed, his face darkened with a faint scruff of beard. He is tall, lean and unfailingly polite. The caustic edge many Australian men display — a good-natured chip on the shoulder that manifests itself in conversational jousting — is absent. Jackman’s casual graciousness seems more British, evoking more the native England of his parents than the rough-and-tumble colony of his birth.

In between amusing his daughter, Jackman gives a starboard tour of the Sydney waterfront, pointing out an oddly extravagant house with a palm tree jutting through its roof (“I’ve been in that house. Inside, it’s literally like you’re in Tahiti. Kind of cheesy”), as well as Nicole Kidman’s expansive three-storey villa. The Jackmans, he says, watched the last New Year’s Eve fireworks with Kidman, Jackman’s co-star in the drama Australia directed by Baz Luhrmann, aboard a yacht that Sting rented for the night. With Kidman’s husband, Keith Urban, on the guitar, “everyone got up and sang a song,” Jackman says. “Then a friend who was staying with me started singing Roxanne a cappella,” a decidedly ballsy move, it would seem, on Sting’s boat. “But Sting said all right, and he got up, too.” Next he points to a dazzlingly white stuccoed Victorian mansion planted on the coastline. “And that house, there? That’s where we filmed the Darwin party scene,” he says, talking about the film Australia.

Australia — and, by extension, Australia — has been a primary focus for Jackman since 2006, when the actor was tipped to replace Russell Crowe in the leading-man slot. (Crowe reportedly dropped out for financial reasons, grumbling: “I don’t do charity work for major studios.”) The second-world-war-era epic has Jackman playing a rough cowboy (or drover) who undertakes a huge cattle drive to save the ranch of a high-strung widow (that’s Kidman). “He brings enormous Aussie charm to the role and this laid-back swagger, which I think hasn’t been seen on screen for a long time,” gushes Kidman. “I think Baz brought something very different out of Hugh.” The film has become something of a national endeavour, not unlike the effort that went into Peter Jackson’s Lord of the Rings, which put neighbouring New Zealand on the map. Luhrmann not only filmed this down-under Gone with the Wind in Australia, he filled the marquee with an entirely Aussie cast and crew and paired up with Tourism Australia so the film could be used as bait for visitors. Then there’s the title: in Australia anyway, definitely a risk. “There’s some anxiety that goes with it,” Jackman admits. “It better be good, right? Australians aren’t going to go, ‘Oh, I didn’t like that,’ if they didn’t. No, they’ll be angry. But Baz has earned the title.”

And Jackman, it’s fair to say, has earned the role. Or any role, for that matter, since in his 10-year film career he has played nearly every kind: the darkly obsessed magician in The Prestige; his Tony award-winning run as the flamboyant, ultra-gay entertainer Peter Allen in the Broadway musical The Boy from Oz; the voice of a penguin in the animated Happy Feet; and the woolly, adamantium-clawed comic-book mutant Wolverine in the X-Men movies.

That kind of range is the definition of the job, but Jackman, 40, extends his brand of method acting to his body as well (Happy Feet excluded). Hence the nine months of daily yoga he practised to pull off the lotus position for 2006’s The Fountain, plus the additional three months’ practice it required to be able to do it underwater — all for a movie barely anyone paid to see. (Yeah, he’s heard of body doubles. Stuntmen, too. Not interested.) Or the total body transformation he achieved to play Wolverine. The former gym-phobe (“I never understood why people went to the gym; I thought it was ridiculous,” Jackman says) undertook a gruelling routine — up to two hours of weightlifting, five days a week. Ditto for Australia, for which the lean actor needed to pack on the thick muscle of an outback cattle drover. “Hugh’s amazing because he has such athleticism,” says Kidman. “He could barely ride at the beginning of the film, but by the end he was a great horseman.”

“For a year and a half I’ve been quite strict on my eating,” Jackman says. He adopted the diet of an Australian bodybuilding champ who “wakes up at four in the morning, has egg whites on dry toast, then goes back to bed so he gets some food in him before he trains at 6am”.

Jackman is so modest he won’t even take credit for being modest, chalking it up to national character. “I love the way in America people go, ‘I’m good at making coffee. I’m going to make you some great coffee,’ ” he says. “Here you’d say, ‘Let me make you coffee,’ and if someone says it’s great, you go, ‘Aw, I just fluked it. Usually it’s crap what I make, but I just got lucky today.’” He offers a variation on that theme when asked about his versatility as a performer. It’s an Aussie thing, he explains. “Look at the business here in Australia,” he says. “With a population of just 20m, you can’t be too fussy. You have to be able to do everything. That may be some of the reason Australian actors have done well. There’s more versatility to what they can do. Plus, we have a saying here: Have a go. We don’t like people who play things safe. It’s not enough just to be successful. You have to take a bit of a risk.”

Have a go, you mug: it’s as good a summation as any for Jackman’s life so far. But it’s slightly misleading at the same time, because while Jackman may sometimes leap without looking, once he leaps his commitment is fervent, and possibly even obsessive. Don’t believe him for a second when he says he just fluked it.

Jackman is the youngest of five children of Chris Jackman, an English-born accountant, and Grace Watson, who abandoned the family and moved back to England when Hugh was eight. It was by all accounts a searing split for Hugh, who was left to the roughshod care of his siblings while his father worked until 6.30 or 7 at night. Though his youth was comfortable — “I was raised in a white, leafy suburb north of Sydney with private schools,” he says — it wasn’t, at least to him, normal. Normality was what he craved, which may be why his earliest ambition was to be an accountant like his dad. “I wanted to do his job,” he says. “He had a calm power about him when he was at work. He had a secretary.”

As with most Australians, a yearning to travel eventually set in. “Part of that is our isolation,” Jackman says. Australia might be a big country, but it can feel like a small island tucked far away from the rest of the world. If we were to turn this boat due east, we’d cover lots of blue — 7,000 miles of it — before landfall in South America.

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