The America's Cup, the 160-year-old elite sailing competition held every three to four years, attracts its share of cutthroat businessmen. But few can match the drive of Larry Ellison, co-founder of the software giant Oracle. According to 'San Francisco Chronicle' reporter Julian Guthrie – whose book 'The Billionaire and the Mechanic' (out this month) describes Ellison's decade-long quest to win the Cup – he has likely spent more than $300 million on three attempts. In one telling scene, a crew member complains about the intensive training not being fun. "Fun?" Ellison snaps back. "You think we're here for fun? . . . If you want to have fun, go buy your own fucking boat."

When Ellison first goes after the Cup in 2000, he learns that teams have to be sponsored by yacht clubs. Bristling at the snobbery and rules of some of the established clubs, Ellison signs with Norbert Bajurin, a radiator repairman who oversees San Francisco's blue-collar Golden Gate Yacht Club. A billionaire 43 times over, Ellison still sees himself as an underdog. Ellison was adopted as a child and grew up feeling as if "he would never amount to anything," Guthrie says. Winning the Cup becomes the ultimate manifestation of his need for success.

Guthrie's interviews with the reclusive 68-year-old were a feat in themselves (Ellison rarely agrees to them). After chasing him for months, Guthrie awoke to a surprise email from Ellison: "Happy to talk. . . ." She met him at his luxurious Woodside, California, estate, catching glimpses of his temperature-controlled garage filled with high-end cars and, at one point, accidentally draping her coat over a Monet leaning against the back of a couch. Ellison took sailing lessons while living in Berkeley in the 1960s and then got into it in earnest in the 1990s, when his Oracle fortune enabled him to build the Sayonara, a racing sailboat. He won a few races, but the America's Cup remained the big prize. "It was the next great challenge," says Guthrie. For Ellison, the process was painstaking. He failed in his first two attempts, in 2003 and 2007, in part because he wasn't directly involved enough with the team: He told Guthrie he considered giving up after the second loss. In 2010, things changed. Ellison took control, going so far as to pilot his own boat – a sleek $40 million trimaran with a 223-foot wing sail – a few times. He won the Cup that year, taking the final race by a whopping five minutes. As he tells Guthrie, "It's hard for me to quit when I'm losing, and it's hard for me to quit when I'm winning. It's just hard for me to quit."

'The Billionaire and the Mechanic' is about more than just Ellison. It's a look at the competitive and high-tech world of the America's Cup – one in which obsessive boat builders search for ultralightweight carbon-fiber "custom blends," hire million-dollar athletes to run their teams, and take each other to court over where races can be held. (They also spy on each other: Last January, Ellison's team had to pay Cup officials $15,200 for taking photographs of the Italian team during training in New Zealand.) Ellison – who buys a Hawaiian island in the course of Guthrie's book – has suffered setbacks on the road to the next America's Cup, to be held in San Francisco in July. One of his boats capsized during a training run, and another crashed. But he remains steadfast in his pursuit. "It's become a business," Guthrie says of Ellison's chase for a second America's Cup, "not just a hobby."