The planet's greatest surfer deserves to be mentioned in the same breath as Michael Schumacher, Lance Armstrong and Tiger Woods

Kelly Slater, who last week won his ninth world surfing championship, is one of surfing's more articulate sons. Interviewed by Drew Kampion, himself an eminence grise of surf journalism, Slater once said: "My belief is that heaven and hell are metaphorical terms for what you make of your life. In any instant, you have the ability to make your life total pleasure or total hell."
The Floridian surfer's latest triumph consolidates an already unparalleled career in professional surfing, one which demonstrates both preternatural athleticism and an extraordinary ability, over countless instants, to make the right decision, in the right place, at the right time.

Slater is, quite simply, the greatest surfer ever. He is but one of a handful of surfers to transcend the sport and, in his overwhelming domination of competitive surfing in the modern era, merits comparison with legends from the mainstream of sporting endeavour – the likes of Michael Schumacher, Lance Armstrong and Tiger Woods. Some would argue that he eclipses them all, for Slater's reign not only spans a remarkable 16 years, but also includes a three-year hiatus during which he didn't compete at all.

Slater sealed his ninth Association of Surfing Professionals (ASP) world title at the Billabong Pro Mundaka, in northern Spain, last Friday. He didn't win the event, because he didn't have to: a third-round heat victory in four-foot surf against local charger Eneko Acero was enough to put him out of sight from his nearest rivals, the Australian trio of Taj Burrow, Joel Parkinson and Bede Durbidge. Emotionally drained, Slater exited the contest in the next round, but with five first-place finishes on the 11-event World Championship Tour (WCT) for 2008 under his belt, Slater could justifiably claim to be surfing better than ever. What makes this all the more astonishing is that in a sport whose practitioners usually peak in their mid-to-late 20s, Slater is 36.

Born in Cocoa Beach, Florida, Slater is both the youngest surfer ever to win the ASP world title, and the oldest. He was first crowned champion in 1992, aged 20, and became the oldest winner at 34 when he won his eighth title. And if he's just set the bar yet higher by vanquishing all-comers at the age of 36, the records don't stop there.

In each heat, the ASP operates a two-wave scoring system in which a surfer's best two waves are aggregated, with a maximum possible score of 20; needless to say, Slater is the only surfer ever to score a perfect 20. He easily outpaces Australian surfer Mark Richards' four ASP titles (the previous record until Slater came along), and has the highest number of contest wins in surfing history (39). For the surfing cognoscenti, Hawaii remains the proving ground, but here, too, Slater has excelled, winning the most prestigious individual event on the WCT, the Pipeline Masters, a record five times.

Mobbed by reporters at the water's edge in Spain, Slater was all but lost for words. "It's going to take a little while to sink in," he said. "I'm probably going to have to call home and talk to family for it to really hit me." But if the man himself needed time to reflect, the surfing world didn't. The eulogies were immediate, and with them, another wave of expectation: will Slater compete again next year, and try to win his 10th title? Slater says he will, but that if he has to end his career with nine titles, he "won't feel frustrated".

Slater's celebrity status has been enhanced by high-profile romances with Cameron Diaz (herself a surfer), Pamela Anderson and Brazilian supermodel Gisele Bundchen. He appeared in several episodes of Baywatch in the early 1990s and, a talented guitarist, he has also performed with Ben Harper and Pearl Jam. Inevitably, there is a hugely successful video game, too – the aptly named Kelly Slater's Pro Surfer – not to mention endless starring roles in surf movies, perhaps the most famous of which is the Jack Johnson showcase, Thicker Than Water.

It's all a far cry from his early years at Cocoa Beach, where Slater's parents, Steve and Judy, experienced debilitating financial problems. The couple divorced when their middle son (Slater's brothers, Sean and Steven, are also excellent surfers) was 11. The boys witnessed their father's uneasy relationship with alcohol, and perhaps, as with so many high achievers, a degree of parental dysfunction contributed to Slater's immense drive. That drive, in turn, has taken him to a wealthy lifestyle which he could never have imagined as a young boy, but his success is fundamentally down to a freakish natural talent in the sea. To watch Slater surf is to be mesmerized by a blend of suppleness, power and elegance allied with an uncanny wave-reading skill. His surfing is so fluid and gymnastic that it's as if he inhabits the ocean, rather merely visits it.

Like his childhood hero and three-time world champion Tom Curren, Slater on land is no less notable. Both walk with a feline grace - a nuanced, barely discernible but subtle awareness of everything in their environment. It's a rare thing, and what's more, Slater knows it. As he says: "Most anything I've ever set my mind to, I could accomplish. I felt like I was always in the right place at the right time." The worry for his rivals is that this time next year, the likelihood is that Kelly Slater will once again find himself in just the right place, at just the right time.