I blame Mr Mant. The careers master at my school, he was full of useful information about Oxbridge colleges, Ucca forms and how to get on in accountancy, law and engineering. But why, Mr Mant, did the D in your carefully collated A-Z of careers contain dentistry and diplomacy, but nothing about becoming a DJ?

Surely this is the best career of all? And if not for your oversight it could have been me, bronzed and happy at the wheel of my giant powerboat instead of Mauro Picotto, superstar DJ from Turin and possessor of a life so gilded that spending time with him is dangerous for the soul. There is his convertible Mercedes SL500, the apartments in London, Turin and Ibiza, the Sunseeker Superhawk 50, the legion of adoring fans and girlfriend so gorgeous you don't know where to look. Oh, and did I mention, he often only works one day a week.

Mauro, 38, tried his hand as a stonemason in his father's yard, but sensibly gave it up for music, and number ones in numerous countries followed. He's huge in South America, has played to stadia of more than 40,000 in Holland and was the first DJ to mix live on Top of the Pops. He's agreed to give me a glimpse of the DJ's life on Ibiza, the world's undisputed clubbing capital. Everyone who has watched Ibiza Uncovered, or read the annual newspaper exposés, knows that on 'Ecstasy Island' the superclubs are vast big tops of sex, drugs and excess, and the DJs are surely the ringmasters. So when Richard, the photographer, and I arrive bleary-eyed after a 6am flight, we're slightly apprehensive. Mauro's manager drives us from the airport past 20ft-high billboards of the star's face, promoting tonight's main event, Mauro's weekly Meganite party at Privilege, the world's biggest nightclub. 'So what time will he be going on stage?' I ask the manager. 'Well, he's playing last tonight, so probably about 5am.'

'Er ... and when will it finish?'

'Last week, about 7.30.'

It's going to be a very long day.

When we finally meet Mauro, on the terrace of the Coastline bar at the foot of his penthouse apartment in San Antonio, he is not popping pills or downing lagers. 'If I have more than two glasses of wine, I am drunk, absolutely,' he says, tucking into a rocket salad. As we talk it becomes clear that these days the highlife of an Ibiza DJ is more about fine food and relaxing outdoors than pills, thrills and bellyaches.

'When I first came to Ibiza nine years ago, it was because it was an important place for a DJ to be, to go to all the clubs and hear all the other styles being played,' says Mauro. 'In those days I was wild. But then I discovered the other side, beyond the clubs. You can go on a boat, swim, relax, go to nice restaurants - you can enjoy a holiday here without even going to a club.'

It's not just that he's grown up. Ibiza is changing. For several years now, doomsayers have been predicting the end of the party for the island. Numbers of revellers at the big clubs are down and the summer season is getting shorter. But the fall is largely down to fewer Brits and Germans coming on bargain packages to drop Es and throw shapes. Their absence is leaving space for an older, more international, and upmarket crowd. Many of the original clubbers are coming back looking for a bit of luxury, and even bringing their kids. Ibiza town's marina is chock full of posh yachts from Guernsey. Don't tell me they are here to rave.

Mauro heads off to start a series of pre-parties and warm-up gigs. Richard and I begin a series of Ellen MacArthur-style catnaps.

Ironically, on an island filled with lasers, smoke machines and vast sound systems, nights always begin with the gentle ritual of watching the sunset. We rendez-vous with Mauro at his favourite sundown spot, Kumharas, a hippy hangout round the coast from 'San An' (-tonio). Market stalls sell Moroccan-style lamps, gypsy skirts and joss sticks. Lots of tanned children career about, bongos are bashed, stilt walkers and mime artists wander past. On the terrace people drink cocktails, and as the huge orange sun dips into the sea, they cheer and clap. It's like a mini-Glastonbury, except the weather's great and just behind the terrace is a fine restaurant.

'The best tuna on the island,' says Mauro, lying back on the cushions that serve instead of chairs. He's had a hard afternoon getting mobbed by fans, signing autographs and posing for pictures. 'It's not that I don't want to be friendly, it's just that at the end of the day, I feel shy. Today is work, but tomorrow we'll have a really good day.'

The owner scurries over to greet Mauro, shakes all our hands, and beams when he hears a track on the DJ's new album is to be named after the restaurant. At the end of the night, there's no bill.

Privilege at 5am is dark and throbbing. Mauro goes on to wild shouts and a sea of arms in the air and when he eventually wraps up, the 4,000 clubbers are calling out for one more. It's 7.45am.

Five hours later we are speeding out across the clear blue waters of San An bay on Mauro's powerboat. At the wheel is Captain Krankl, dressed in a distinctly un-nautical track suit in bright red, yellow and green. Mauro is feeling rough but upbeat: 'I was in bed feeling awful, but to spend my little hangover on the boat is much better. Being in the middle of nature charges you with positive energy.'

Krankl also confesses he's been up all night. 'In Ibiza we have a saying,' he tells me quietly. 'Night is happy, morning is sad.'

Of course powerboats like this - a big pointy Sunseeker with a special Arneson drive to give a huge plume of spray (and make it more stable or something) - are just penis extensions for the nouveau-riche, flash mid-life crisis materialism which under normal circumstances I'd be the first to sneer at from the harbour wall.

Except when you are actually on one, zooming past sailing boats at 45 knots, it's really rather fabulous. The speed immediately kills the sweltering midday heat, and makes everyone's hair fly back dramatically (except for Richard and me who are holding on to the matching sunhats we've bought to save our white faces). It's like we've snuck into a Duran Duran video.

We head out to explore some of Ibiza's natural wonders. First is Es Vedrà, which looks like a limestone iceberg rising from the sea. The sea all around is shallow and turquoise, but here the seabed plummets and the water is the colour of blue-black ink. Krankl explains a hermit once lived in a cave on the rock and locals credit Es Vedrà with mystical powers. Many come to scatter their loved ones' ashes in the deep water or to touch the rock face for a year's good luck.

Next stop is Atlantis, a stunning, desolate stretch of coast where in the 1960s hippies came to camp for weeks under a giant rock. More recently Kate Moss was here for a photo-shoot, while Mauro's boat, chartered by paparazzi, clicked and whirred away nearby.

We swim in the crystal water at Cala Llentrisca. The ringing in our ears from Privilege's sound system is replaced by the throb of cicadas.

Soon it's time for refreshments and we speed around the coast to Cala Jondal. Here the sea resembles a parking lot for superyachts, and the beach is backed by hills cloaked in pine forests. The draw for the 'wet set' is the chic beachfront bars, the Blue Marlin and Jemanja, and Es Xarcu, a posh restaurant across the bay. But when you're a superstar DJ, you don't even need to go ashore. Krankl places a call and within a few minutes two waiters are rowing out to us in a dilapidated dinghy holding aloft a jug of sangria. 'The best on the island,' grins Krankl.

We speed back past the millionaires' villas along Cala d'Es Cubells, pause to take a few snaps of Elle Macpherson's house, then go to Café del Mar, another legendary spot to watch the sunset at the start of another long night.

Tonight though, Mauro is off duty, so instead of a club we head into the hills to Sa Capella, a restaurant in a 16th-century church. San An's West End strip of boozing, fighting and spewing is 10 minutes' drive away, but in a different world. Candlelight plays on the rough stone walls. The diners are a mixture of smart couples and families. We're told it is also a favourite of big name DJs - after a night of boom, boom, boom, they clearly yearn for nothing more than the muted music of wine glasses, cutlery and conversation.

Mauro, perhaps unsurprisingly, is in contented mood. 'On Ibiza I feel no stress, I feel at home. When you watch the sunset from the boat, it's like there's a magician in the atmosphere.' It strikes me that as well as being fabulously rich and popular, he's also great company. Jealousy, I remind myself yet again, is unattractive.

The following day he jets off to play at a new superclub in Montpellier. We catch an early morning Easyjet back to reality.