Prince William and Kate Middleton
The Duke and Duchess of Cambridge pose with members of the 1851 Trust charity as they visit the Land Rover BAR at the America's Cup World Series on July 24, 2016 in Portsmouth, England. AFP/Getty

The Duke and Duchess of Cambridge hit the high seas as they cheered on Sir Ben Ainslie's America's Cup team to victory on Sunday 24 July.

The royal couple joined thousands of spectators to support Sir Ben's Land Rover BAR team, during the Portsmouth leg of the America's Cup World Series (ACWS).

Sporting the shirts of the Olympic Champion's team and emblazoned with their official titles, William and Kate enjoyed a ride on a high-speed catamaran travelling at speeds in excess of 40 knots during the three races of the afternoon.

Taking their seats in the front of the twin-engine vessel, bearing the royal standard the royal couple looked thrilled as they watched Sir Ben's catamaran sail to victory in the final race.

Prince William and Kate Middleton
The Duke and Duchess watched the races from a twin-engine catamaran AFP/Getty

After the race, the Duke and Duchess returned to dry land at the event village, where they presented the winner's trophy and medals to Sir Ben and his team. .

Prince William and Kate Middleton
Kate Middleton and Prince William cheers on Sir Ben Ainslie as they sail past after winning the final race AFP/Getty

Sir Ben Ainslie's team won races two and three of the afternoon, leaving the team in joint first place with Groupama Team France, the Mail Online reports

Surrounded by cheering spectators, who had turned out in their numbers to show support, Sir Ben said: "The guys did an incredible job with the boat handling and to be able to do that in front of you guys is what it's all about for us, so thank you."

Prince William and Kate Middleton
Catherine, Duchess of Cambridge presents Sir Ben Ainslie with the America's Cup 2016 trophy on stage at the America's Cup World Series AFP/Getty

Earlier in the day, the royals visited the crew's base in Portsmouth, where they were given a tour of the boat shed which houses the team's state-of-the-art testing vessels. The royal couple were welcomed by a group of young aspiring sailors, who had been out with the team ahead of the scheduled races.

Kate Middleton
Kate Middleton wears a team jacket sporting her official title AFP/Getty

10-year-old Zak Kay, from St Paul's Catholic Primary School in Portsmouth - who won a competition to design the winners trophy for the Portsmouth ACWS event - asked Prince William what Prince George had received for his birthday on Friday (22 July). William replied: "I am not telling, he got too many things, he's far too spoilt, he's not into boats yet."

Prince William and Kate Middleton
The royals cheer on Sir Ben Ainslie and his crew AFP/Getty

After a quick change, the Duke and Duchess boarded a small vessel to go out and watch the six teams taking part in the second and final day of the racing.

Kate is the royal patron of The 1851 Trust, a team Land Rover BAR affiliated charity . The charity is aimed at getting children involved in the maritime industry. In February 2016, she visited the Land Rover BAR team headquarters in Portsmouth to launch two initiatives aimed at involving children and young adults from diverse backgrounds, concentrating on sailing and the technological dynamics of the sport.

Prince William and Kate Middleton
The Duke and Duchess chatted with the aspiring young sailors AFP/Getty

In May 2016, Kate took over the controls of a Land Rover catamaran as she kicked off the world yacht challenge.

39-year-old Ainslie, who is the most successful Olympic sailor in history, said the Duchess was such a capable sailor he would even give her a place on his team as the charity prepares to race in the America's Cup in 2017.

Prince William and Kate Middleton
The Duke and Duchess of Cambridge congratulate the British team on their win AFP/Getty

The finals of the America's Cup World Series (ACWS) is due to be held in Bermuda in 2017. If Sir Ben succeeds in leading the team to victory it will be the first British win in the events 165-year history.