It is hard to know which is the most treacherous, the capricious Meltimi wind which sneaks up on unsuspecting mariners around here with a sigh and a brutal ambush or the fine line between Olympic glory and shame. Either way, sailing into the lee of Ben Ainslie is, in these days of all days, like coming out of a storm.
What you find is the certainty that comes only with the ultimate belief that you have pushed yourself fiercely enough to every known limit that victory is as much a right as an achievement.
"My position is simple enough," says Ainslie, "I'm not saying I'm going to win, but I know what I have to do to get another gold and I'm prepared to do it." It is a commitment to a level of ambition that is arguably unparalleled in the history of British sport. This includes, stunningly, the making of a new body.
This week the favourite to win a third medal, and second gold, submitted to both a drugs test and another standard procedure for a British Olympian after the Scottish skier Alain Baxter's careless use of a decongestant before winning and losing silver in the Winter Games - a thorough examination of his box of medical supplies.
Ainslie shrugs at the necessity of it because he knows that strange things happen out there in the wider world of sport - and he says, "We don't have a drug problem in sailing but you have to live in the real world, and it's terrible to think about what happened to Alain Baxter.
"I don't know what the future holds for me, how many more Olympics I will compete in after this - but I do know that when it is over I'll be completely drained. You cannot come to the Olympics and hope to win if you don't cover every single detail."
As this 27-year-old, who some hard critics believe may be the most brilliantly instinctive sailor his country has ever produced, tells you matter of factly about the astonishing regime which has piled on 40lb of muscle since his decision to move from the Laser-class to the heavier Finn boat two years ago, you are bound to go back eight years to the house, draped in the union flag, amid trees on the banks of the Savannah river.
That is where this jewel of an Olympic story first began to shine in the Games of Atlanta. Then Ainslie's father, Rod, a winning round-the-world yachtsman in his time, told you why he and his wife had sold the family home in the West Country and slashed into their retirement fund to give their son his chance to beat the world.
"I didn't see any alternative," said Ainslie Senior. "It would have been a terrible thing to deny his talent. When he was four years old he sailed us out of a French harbour without giving a moment of concern. When he went to the Royal Yachting Club for special coaching, they taught him to use a compass, but he said straight away he didn't need one. He said to me, 'People can get lost using a compass'." The Ainslie family couldn't afford to follow their teenage son's superb duel with the Brazilian star Robert Scheidt on a $100-a-day launch. They picked up snippets of news on television text and local radio in their rented condo, and groaned when the Brazilian lured his precocious challenger into the disqualification in the last race which made the difference between gold and silver.
Now, Ben Ainslie recalls with some emotion the moment of revenge in Sydney four years ago, when the positions where reversed after he had sailed with such ruthlessness his effigy was was later burned in the streets of Scheidt's native Sao Paulo.
"After it was all over my father and I went off together and talked about everything that had happened since he first started to help me in my career. It was very, very emotional. My father asked me if it was all worth it, my sacrifice, his sacrifice, my family's, and I said that it was, and every second of it. I only had to look at him to see how he felt." Now in these days when so many potentially great sports careers are trapped by the demands of celebrity and commerce, Ainslie's status among both competitors and team-mates is touched by awe.
Joe Glanfield, who with his team-mate Nicky Rogers, was denied a bronze medal in Sydney in the 470 class by a single point, was asked this week about the impact of Ben Ainslie. "You look at him," said Rogers, "and you see another Steve Redgrave, and of course you are inspired. There is nothing he won't put himself through to win."
The phenomenal weight gain has been created by four high-protein meals a day, as much ice cream as he believes it is reasonable to consume, and a vigorous programme in the gym. He glows with both health and the conviction that what he has is not so much a challenge as a privilege. He says that the possibilities of Olympic sport, and then, one day, his ultimate ambition to skipper a winning British yacht in the America's Cup, are boundless. His girlfriend, Beth Boel, sails and is a marine biologist. It is as though Ainslie has bound himself only by the sea and its mysteries.
"I think the work has been done well enough since I went down with a virus at the start of the year and I'm comfortable now with local conditions," he says. "The Meltimi is strong and shifting but I think I understand it as well as anybody apart from maybe the Greek, Emilio Papathanasiou." Aficionados say that Ainslie has just one threat, the extrovert Pole Mateusz Kusznierewicz, who won the European championship this spring while Ainslie was still finding his sea legs after a bout of glandular fever. But he demurs, saying, "Looking down the list, I can see as many as 10 potential winners. But that only makes me more determined."
Ben Ainslie has won the last three world championships. He did it as relentlessly as his father believed he would when, with the help of a friend, he carried an eight-foot dinghy into the bedroom of his sleeping 10-year-old son. "When Ben woke up," Rod Ainslie recalls, "he thought he was still in a dream." Here over the next week or so the suspicion must be that it will remain unbroken.Reuse content