It's a tradition in sailing to have a "nipper" aboard. That's the beloved youngster on the crew, who learns navigation, sailhandling, marlinspike seamanship and the like from crusty old crewmates.

OneWorld, the Seattle entry in the America's Cup, has a nipper, but instead of doling out sandwiches and lending a hand grinding winches, he nearly runs the show.

At the tender age of 23, Australian James Spithill would be the youngest helmsman ever to steer a boat in the Cup, except he would have to replace himself for the honor. He was helmsman for Syd Fischer's hapless 1999-2000 entry last time, the aptly named Young Australia. He started driving that boat at age 19.

If ever there was a child prodigy in yacht racing, it's fair-haired, freckle-faced Spithill. He'd been racing keelboats considerably less than a decade when he took the helm in Cup trials the first time. Now he's in the driver's seat on a fast boat backed by two billionaires that could make it deep into the competition.

None of which seems to faze him. Of all the helmsmen in this Cup, none looks as calm and collected at the wheel as Spithill. He's Cool Hand Luke, apparently as comfortable on the water battling grizzled Cup veterans as he would be on land sipping tea. It's no surprise, given his background.

Spithill grew up in the Sydney suburb of Pitwater, where his father commuted to work as a teacher by outboard-powered metal skiff. Where they lived, cars couldn't go.

"When I got in that tin boat at the end of the day," Arthur Spithill said, "I left the world behind."

Pitwater is a lush hamlet 15 miles up the coast from Sydney. There, young James Spithill got his first craft -- a Windsurfer -- from Santa Claus at age 5. "It was an awesome way to grow up," he said. "To get to school, get your groceries, go shopping, everything was by boat.

"We had television, but I can't remember watching it. There was always something to do -- go out in the bush with your mates, windsurf, go up to the waterfalls, muck around in dinghies and powerboats."

Arthur Spithill gave James and his two siblings, 20-year-old Katie and 14-year-old Tom, freedom to follow their hearts and it took them to boats. "My parents came through the depression. They had a very clear program for me -- get an education, get a job, get a house, get a car. There was no time for sports or fun. I went to university for 11 years to end up somewhere, and when I got there, I didn't know why I'd bother," said the elder Spithill.

Young James by contrast started racing dinghies at the local boating club at age 8 and got his first keelboat at 12, a 20-foot Manley Junior as a gift from a neighbor. He started racing it with sister Katie and they began winning. Within six years he had won the Junior World Match Racing championships twice, then watched Katie defend his title and win over male rivals when he got too old to compete.

His father coached them both in match racing and put James and Kate into boxing lessons to toughen them up. James excelled at both. "At one point, people were trying to get him to go for the Olympics in sailing and boxing. I thought, hang on, if he picks boxing all I have to buy is a pair of gloves and some shoes. That's a lot more affordable than sailboats," said his father.

But sailing won.

James and Arthur Spithill are look-alikes, both with ginger hair and carefree, unlined faces. Arthur has watched and coached his son at every level, and last week was out on a spectator boat watching the young man racing at the highest level of international yachting.

Surprised? "Not really," said the father. "It's just a continuation of what we've been doing for the last 10 years. It's the same thing, just further up the scale."

The race between OneWorld and Prada that day was close, with OneWorld holding a slender lead most of the way until Prada caught a favorable wind shift late in the game and won. Arthur Spithill was among the calmest people on the spectator boat, shaking his head and chuckling ruefully at the tactical error that let Prada go by.

Calmness is the trait he prizes most. "I've coached match racing for quite a few years," said Arthur Spithill, "and I can tell you no matter how talented a young racer is, he will never be any good unless he has one thing: composure."

James Spithill wins high marks for that from his crewmates on OneWorld. "He's very mature, very calm in a crisis," said skipper Peter Gilmour, who is Spithill's mentor aboard.

Added Richard Dodson, a veteran New Zealander who is strategist on the boat, "We told James when he got the job as helmsman, just worry about starting the boat and steering, we'll get you around the track. He's very quiet. He just does his job."

Arthur Spithill thinks the training in boxing helps keep James cool. "In that game if you make a mistake, it costs you right away, so it makes you more aware, keeps you on your toes." And, he said, the ability to keep levelheaded when wounded is as invaluable in boxing as it is in match-racing, where the combat is head-to-head and there's no room to cloud judgment by getting angry.

Was young Spithill surprised to get the nod as helmsman on a boat full of older, more experienced sailors, including some very good helmsmen? "Not really," he said. "All my life I've been the youngest guy on the boat. I was steering Ragamuffin [Syd Fisher's 50-foot ocean racer] when I was 18 with a pretty experienced bunch of guys. I was the youngest by far, but I'm used to hanging around with older people, and they gave me respect when they saw I could do the job."

Spithill says his experience on Young Australia was a perfect preamble to the high-stakes game he's playing on $75 million OneWorld. "We learned a lot last time. There were a lot of young guys on the team so we had a lot of enthusiasm. It was exciting just to get close to someone you'd been watching all your life. The faces on the boat just lit up.

"We'd work hard, sail hard and party hard, and it set us up well for this time around."

America's Cup Note: Racing was canceled Saturday for the 16th time this season as strong winds swept the Hauraki Gulf. Alinghi leads Oracle/BMW, 3-0, and Prada and OneWorld are tied, 1-1, in best-of-seven challenger semifinals. Racing will resume Sunday.

OneWorld's James Spithill grew up on the water near Sydney where he raced dinghies at 8. "It was an awesome way to grow up."SPITHILL