“There’s a boat back there!” yelled Sandy Oatley, 64, the avuncular head honcho of Hamilton Island and billionaire scion of the Australian wine and real estate family.

Usually he’s at the wheel of his 92-foot, AU$7 million ($5 million) motor yacht, Andiamo, which he personally designed (locals call it “Sandiamo”). Last Thursday, Oatley was standing on the aft deck, hosting some 30 Australian business titans and friends over cases of chilled Piper-Heidsieck, when suddenly a sailboat appeared to be about to strike his vessel on the starboard side. Two seconds before collision, Oatley’s captain opened up the yacht’s twin jet engines, and the craft slipped past in Andiamo’s wake.

“I got his boat number,” Oatley whispered to an aide. “Let’s send him a case of beer or something,”

In most of the Seven Seas, angry words (perhaps even a middle finger or two) would have been the norm. But this was day four of Audi Hamilton Island Race Week, the nexus of Australia’s high society, when a stiff upper lip and a sense of humor is mandatory. Just that morning, a multi-hull race had to be postponed when a trimaran ran into a catamaran—“circumcising it,” as several participants joked.

Australia’s Ascot

The race traces back to 1984, when a group of wealthy sportsmen got the developer of Hamilton Island, Keith Williams, to host the event as a way of drawing attention to the island’s fledgling hotel, then a farther downmarket package-tour destination. Now, it's one of Australia’s biggest annual social events. This year's tony doings ran from Aug. 15–22, with 202 boats and approximately 11,000 spectators and sailors crowding the two-mile by three-mile island. Major yacht owners included Hong Kong department store billionaire Karl Kwok, with his 80- foot water slicer, Beau Geste; an Oatley yacht, Wild Oats X, skippered by Mark Richards, fresh from his eighth Sydney-to- Hobart win; and Robert Salteri, billionaire heir to the Tenix construction fortune, in his 54-foot, seagoing Ferrari.

Just across the harbor next to the finishing line, Lachlan Murdoch’s AU$40 million racing yacht, Sarissa, was anchored so that his family—including his father, Rupert—could watch the proceedings from a safe distance.

While the big fellas were out on their boats, a battalion of SWAGs—local speak for “sailors' wives and girlfriends”—were left on the island to mingle, nibble beneath big hats at lavish banquets, and perhaps pick up a AU$100,000 Paspaley pearl necklaces or other glittery things in the pop-up stores lining the harbor. Everybody was whirring by in golf carts along the marina's Front Street like a pack of fabulous Jetsons. With Tanqueray pop-up bars, live bands, and public peacocking, the scene looked like an Australian version of Ascot. (There were quite a few male landlubbers and female sailors, too.)

The kangaroos and cockatoos in the jungle kept to themselves.

Semi-Private Island

Hamilton Island itself could be described as Australia’s Nantucket—were Nantucket owned by a single family.

After making a fortune founding Rosemount Wines (sold in 2001 for AU$1.1 billion), flamboyant 87 year-old Bob “Popeye” Oatley bought the island, a lush green dot 16 nautical miles off the northeast coast of Queensland in the Whitsunday archipelago, for AU$110 million 10 years ago. The family then poured an additional AU$400 million into upgrading its facilities. The jewel in the crown is the Qualia resort, a Relais & Chateaux property that opened in 2008 on the island's northern tip. There, 60 plush teak-and-glass pavilions are accessed via a Jurassic Park-like electric gate: discreet stone, steel, and teak set in impassable jungle. (About two-thirds of the island remains wilderness.) Its Beach House bungalow, said to be Oprah's favorite, with private pool and the best view of the regatta, went for AU$2,900 a night during race week.

Audi may put AU$1.3 million ($950,000) into its annual sponsorship, but the Oakley family puts in a lot of personal funds as well. Despite the island giving itself over to the week—package holiday resorts, conference centers, six high-rise apartment rentals, all booked—the Oatleys told me the race was essentially a loss leader to attract media attention while indulging their own sailing passion. (Surprise, it has worked.) 

Truly Arriving

To get here is simple: You can take a 30-minute ferry, book daily flights from around the country, or fly privately, as many locals do. During race week, the one-runway airport showed private planes lined up like minivans at a suburban mall.

Arriving is another thing. As a journalist on a two-hour commercial jet from Sydney, I saw plenty of boisterous glamor. Coiffed socialites mingled with posh-accented sailors in the open aisles at the back of a Virgin Australia plane, plotting, socializing, and flirting. (No air marshals here, mate!) At one point, a small fashion show erupted from one the rear lavatories. “Too much?” a twentysomething asked as she emerged from the starboard head. “Naaaw, shows off your admirable rear,” said one of the blokes. “McQueen,” the girl said smugly, name checking the designer. It was a mile-high Anna Karenina, with a 737 substituting for the ballet theater.

What would the island’s original inhabitants, the Ngaro Aboriginal people, have said to all this hubbub? They navigated these islands in three-piece bark outrigger canoes, snagging green sea turtles, coral trout, and parrotfish with bone-tipped spears. After at least six millennia in the area, all they left behind are ochre paintings of marine life in some sea caves. Today, members of a distant tribe—Kylie Minogue and Johnny Depp, who was filming the latest Pirates of the Caribbean sequel nearby earlier this year—ride golf carts along the old hunting paths. 

A Whale of a Time

The races take place amid a maze of the 74 pine-covered and mountainous Whitsunday Islands, named by Captain Cook in 1770 as he sailed through them on Britain's Whitsunday holiday. Last week, the yachts shared the waters with the vanguard of some 20,000 humpback whales migrating north toward warmer waters. Crew members were frantically pulling iPhones from waterproof jackets to shoot cetacean mothers and calves doing sudden ballet leaps out of the water among the boats.

“The mother whales won’t eat for the entire three-month journey, so they can keep their full attention on the calves,” Sandy Oatley told me aboard his yacht. (His father, the sail week's traditional king, was missing due to a knee injury.) 

More Champagne

A social highlight of the week came on day six, when tuxedos mixed with miniskirts and ball gowns at a dinner for Sydney designer Collette Dinnigan, who put Madonna into a bustier and Halle Barry in her trademark sequins. Judging from the figures of some SWAGs in their skintight dresses, one suspects that the humpback’s migratory dietary habits were being mirrored on land.

In the middle of the long table, Francesca Packer Barham, Kerry Packer’s granddaughter, canoodled with her tattooed rocker boyfriend, Tyson Mullane, while vintage 1999 Piper-Heidsieck rosé champagne was generously poured. “Drink carefully,” the marque’s managing director, Robert Remnant, yelled in his Old Etonian accent. “Sandy bought out almost all our cases, so this is the last time we’ll get a chance to drink it.”

Meanwhile Sandy’s daughter held court with the family business's brand manager, Vogue-cover beautiful Nicky Tindill. Most of the partygoers were Tindill's friends. “I’m in an interesting position,” she said, nodding at her new husband, Troy, who works for the America’s Cub Syndicate. “I don’t even like sailing.” 

On the Water 

Despite all the island’s wealth and glitter, Kwok, Oatley, and their fellow billionaires were facing spartan conditions on board their stripped-down championship boats. Many had stuffed sandwich rolls into their pockets, since even the plug-in microwave oven’s on Oatley's craft had been jettisoned to minimize weight. Such furnishings as there were consisted of narrow, tennis racket-like mesh boxes: the bunks. From the shore, I could hear the captains bellowing orders to trim sails and shift sides during tacking maneuvers.

“On the boats, there are the professional skippers,” said Hamilton Island Chief Executive Officer Glenn Bourke. “Everyone else, including the owners, are treated as ballast.” 

Collisions and the unpredictable winds—which brought top speeds of around 23 knots (for comparison, the average weekend sailboat cruises around around 6 knots an hour)—weren’t the only hazards last week. The islands are the gateway to the Great Barrier Reef, visible on clear days by waves breaking over coral on the horizon. Unmarked underwater obstacles usually claim a keel or two.

“We’ve got unique tactical sailing conditions out there,” noted Bourke on the appeal of the regatta. “With all the changing winds around each island, underwater obstructions, and the strong currents, it’s a real navigational challenge getting around.”Final Tally

On Saturday, the closing day of the race, the SWAGs wore designer gowns while the sailors kept to their jeans and t- shirts for a final, rowdy beer and champagne presentation dinner. This year, as in the last one, Karl Kwok picked up the big A Division trophy and split modest AU$20,000 purse. Matt Allen, a former investment banker and head of UBS Japan, now overseer of Australia's Olympic racing team, came in second with his new racer, Ichi Ban. 

Perhaps the most important achievements were announced in a speech by Bourke.

“You consumed 106,000 beers, six tons of beef, 3,000 sausage rolls, and ... one apple.”

Being a rugged sort of Australian, Bourke neglected to mention the 3,000 bottles of mostly vintage champagne, 12,000 boxes of strawberries, and a small volcano of in-season Tasmanian truffles that had also been consumed.

In other words, snack food for the humpbacks.