HAMPSHIRE Olympic sailor Sir Ben Ainslie was joined by the Duchess of Cambridge as he launched Britain's bid to win the historic America's Cup yacht race today.

The four-time Olympic gold medallist wants to enter a British team in the 35th America's Cup, to be held in 2017.

The Duchess' support for the team will be a long-term commitment and will see her ''getting out there'' to back the challenge, said a Kensington Palace spokeswoman.

Daily Echo:

The Duchess of Cambridge and Sir Ben Ainslie with the America's Cup

Sir Ben was famously employed as a tactician during the last America's Cup race, helping the US Oracle team overturn an 8-1 deficit to beat New Zealand.

The race first took place off the Isle of Wight in the mid-19th Century - but a British team has never won it.

Sir Ben and Kate met supporters of the bid at the National Maritime Museum in Greenwich.

Sir Ben, who is the most successful Olympic sailor of all time with four golds and a silver, said he had a burning desire since he was a child to be part of a British America's Cup bid.

The sailor, who will skipper the team, said: ''We want to bring it home, it would be an amazing thing for this country.''

Sir Ben added: ''I had this burning desire and ambition to be part of a winning America's Cup team and ultimately a winning British America's Cup team and so was very fortunate to be involved with Oracle last time.

''That was a fantastic experience a great team, we have a lot of respect for them, for team New Zealand, all of the other competitors - but we want to win this for Britain.''

The Duchess met crew and boat designers, and saw an America's Cup class boat, during a breakfast reception.

The oldest trophy in sport was first offered as the One Hundred Pound Cup in 1851 for a race around the Isle of Wight, witnessed by Queen Victoria.

The first race was won by the schooner America, from New York, which beat a fleet of British boats sailing around the island.

American teams successfully defended all challenges for 132 years, until an Australian team won in 1983.

Sir Ben, from Lymington, added the entry of a British team it depends on the development of design and technology skills in the UK, to ensure that Britain has the technological expertise to build a boat capable of winning the cup.

Sir Ben has revealed multi-million pound plans to build a centre of excellence for designing and building a boat capable of competing in the competition in Portsmouth.

Kate, who wore a Jaeger dress, is a keen sailor who watched some of the London 2012 Olympic racing on the Isle of Wight.

Former Channel 4 boss Lord Grade said of Kate: ''She's a keen sailor, she loves her sailing clearly, you can just tell. You can see it in her eyes. It's great for everybody she's got behind it and supporting it.''

Lord Grade, a board member of Britain's bid to win the America's Cup added: ''We've got the best chance we've ever, ever had. It's not going to be easy, but I don't think Ben would risk his reputation if he didn't believe we had a real chance of winning.''

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Lord Grade is a board member of Britain's America's Cup bid

In his speech at a private reception for team members and sponsors held at Queen's House in Greenwich, he said, with the trophy nearby: ''At 163 years old, the America's Cup here is the oldest trophy in world sport and Britain has never won it.

''The first race was organised by the Royal Yacht Squadron and was around the Isle of Wight. It was open to yachts of all nations and 18 were entered.

In 1851 America won this nascent contest for maritime supremacy, outclassing the rest of the field to be the first at the finishing line at Cowes - of course.

''The black schooner won a 4ft high trophy called the Hundred Pound Cup and to honour that victory it was renamed the America's Cup and became a challenge trophy.''

Sir Keith Mills, also a board member, said Sir Ben had offered to take Prince George out on the water when he is old enough, and Kate readily agreed.

Sir Keith, who was deputy chairman of the London 2012 organising committee, said of the Duchess: ''We were all sharing sailing stories and sailing is in her family.''

Daily Echo:

The Duchess of Cambridge with Sir Keith Mills

He added that they would be inviting Kate to watch the 2017 race - whose US course has yet to be announced.

Later at a press conference to officially launch Britain's bid to win the race, he said: ''The most important thing about today's announcement is to get the whole of this country behind the Ben Ainslie racing team.

''Without the support of the whole country we aren't going to be able to attract the commercial sponsors that we need and we know that Ben has a huge following out there.

''So the Duchess has lent her support to the team to help us raise the awareness of what we're doing, and over the next few months we hope she will be involved in some very specific things.''

Before leaving, Kate posed with Sir Ben and leading members of the bid team alongside the America's Cup.

In the background was an America's Cup 45 class twin hull vessel, which will be used for training and racing up until the event starts, when another class of yacht will be used.

Professional yachtsman Freddy Carr, who is part of the Olympic sailor's crew, praised Kate's sailing abilities.

He said: ''She was down in New Zealand in Auckland, sailing with their team on the New Zealand America's Cup yachts, and did very well.

''If Ben's not up to the job, we'll get Kate.''